Alexander Zverev believes he will form a big three with Novak Djokovic and Daniil Medvedev in 2022 but hopes he will not get the chance to become world number one at the Australian Open.

The German is knocking on the door near the top of the rankings after a fine year that saw him win six titles, including the season-ending ATP Finals in Turin and an Olympic gold medal in Tokyo.

Zverev, currently ranked third, could go top of the rankings if he wins the Australian Open, which starts next month, but that is only possible if current world number one Djokovic does not play.

And Zverev is hopeful the Serbian will take part despite continued uncertainty over his participation in the tournament amid intense debate over his COVID-19 vaccine stance.

Djokovic, a nine-time Australian Open winner, is yet to disclose his vaccination status.

Tournament chief Craig Tiley said this week he is still hoping to see the tour's top player participate if he meets the required conditions, which are either being vaccinated or having a medical exemption.

"The situation with Novak and Australia is still a big question mark," Zverev said in a podcast appearance with Eurosport Germany. 

"Of course, I hope that he will be allowed to play, that is very clear.

"There are thousands of mathematical calculations, if he doesn't play Australia and I win the Australian Open, then I'm number one in the world and so on and so forth.

"At the end of the day, now is not the time to think about [being world number one]. Now is the time to prepare as best as you can so you're physically able to play for it."

As well as his silverware, Zverev made the last four of the French Open and US Open, and the 24-year-old believes his experience has begun to come to the fore.

Zverev had a 59-15 record this season and recorded at least one victory against every other player inside the top 10 of the ATP year-end rankings.

"I've become much calmer and I'm also getting older," he added.

"I'm not 18 or 19 anymore. I understand maybe a bit more things about life and understand that you just have to keep calm in important situations. That has had its effect on me this year.

"I think next year could be very similar to the last six months from this year.

"Before, there used to be always talk about Rafael Nadal, Roger Federer and Novak Djokovic – now the big titles were the Olympics, US Open, Turin and Wimbledon, and they were all won by Medvedev, Djokovic and me. 

"I don't expect it to be any different next year."

Andy Murray will compete at the Australian Open for the first time in three years after being awarded a main-draw wildcard.

Murray has finished as a runner-up five times at Melbourne Park – most recently in 2016 when he was beaten by Novak Djokovic 6-1 7-5 7-6 (7-3).

The Scot has since struggled with a hip injury that had him on the verge of retirement, while he dropped to 134th in the world rankings.

However, the former world number one was in action at the Mubadala World Tennis Championship in Abu Dhabi last week, where he defeated Rafael Nadal before eventually falling to Andrey Rublev in the final of the exhibition event.

Murray was due to feature at the Australian Open in 2020 before a positive coronavirus test stopped him from playing, but the 34-year-old is thankful for the chance to compete in Melbourne again.

"I'm really excited to be back playing at the Australian Open and grateful to Craig [Tiley] and the team for the opportunity," Murray said on his wildcard, as quoted by the tournament's website.

"I've had some great times in Australia playing in front of the amazing crowds and I can't wait to step back out on court at Melbourne Park."

Tournament director and Tennis Australia chief executive Craig Tiley added: "Andy is renowned for his fighting spirit, passion and love of the game, and I'm delighted to welcome him back to Melbourne in January."

American Stefan Kozlov and Frenchman Lucas Pouille join Murray as the men's singles wildcards so far, with the other four spots likely to go to Australians and another to an Asia-Pacific player.

The Australian Open gets underway on January 17 with the final set to take place 13 days later.

Australian Open chief Craig Tiley wants Novak Djokovic to participate in Melbourne but will not ask the world number one to disclose any medical reason he has for being unvaccinated against COVID-19.

The first grand slam of 2022 begins on January 17, but it is unclear if reigning champion Djokovic will be competing.

The Serbian, a nine-time Australian Open winner, is yet to disclose his vaccination status.

Following guidance from the Victoria state government, all players, staff and spectators at Melbourne Park must have been fully vaccinated against coronavirus or hold a medical exemption.

Djokovic has been named on the list for the draw and is also due to represent Serbia at the ATP Cup in Sydney, which runs from January 1 to 9.

"If Novak shows up, he'll be vaccinated or have a medical exemption," Australian Open chief executive Tiley told the Australian Associated Press.

"If any player, fan [or] workforce is on site here, you're either vaccinated or you have a medical exemption that's approved and you're on the Australian Immunisation Register.

"That provides us with safety and an extra level of comfort on site.

"We want to have the best players here; I'd love to have Novak here. If he meets those conditions then great, if not, it's disappointing."

Tiley added he does not expect Djokovic to reveal any medical reason for which he may not have received the vaccine, should he receive a medical exemption to feature in the tournament.

"Medically, he doesn't talk to anyone about it. I'm not going to ask Novak that, it's none of my business," Tiley continued.

"[It's] his choice on his medical condition, it's his choice to keep personal and private like all of us would do with any condition we may or may not have. We are not going to force him or ask him to disclose that.

"[If he is here] I will know that he fulfils one of those conditions."

Rafael Nadal is set to play in Melbourne, though that is in doubt after the Spaniard tested positive for COVID-19 this week, following his appearance at the Mubadala World Tennis Championship in Dubai.

Tiley, however, believes Nadal will have recovered in time.

"I'm confident Rafa will be here," said Tiley. "Players that are testing positive now will complete a period of time until they are no longer infectious and they will be fine.

"If you are going to test positive and you want to play the Australian Open, your timing would be now."

Tokyo Olympics gold medalist Belinda Bencic has tested positive for COVID-19 ahead of next month's Australian Open and is experiencing "severe" symptoms.

World number 23 Bencic returned a positive test, along with Ons Jabeur, after competing at the Mubadala World Tennis Championship in Abu Dhabi.

The pair are the third and fourth players to have tested positive after travelling to the Abu Dhabi event, following 2021 US Open winner Emma Raducanu and 20-time major winner Rafael Nadal.

Bencic wrote on Twitter: "Unfortunately and even though I am fully vaccinated, I recently tested positive for Covid-19.

"I am currently isolating and taking all precautionary [measures] to get through this as best as possible as I am experiencing quite severe symptoms (fever, aches, chills)."

The Mubadala World Tennis Championship typically serves as a warm-up event prior to the Australian Open which is due to begin on January 17 in Melbourne.

World number 10 Jabeur, who defeated Bencic in Abu Dhabi, is experiencing "strong symptoms" and isolating in her native Tunisia.

Rafael Nadal has tested positive for coronavirus on his return to Spain, leaving his participation at the Australian Open in doubt.

The 20-time major champion played at the Mubadala Tennis Championship in Abu Dhabi last weekend and declared his mission a success despite consecutive defeats on his return from a foot injury.

Indeed, Nadal had only competed in two matches since losing to Novak Djokovic in the French Open semi-finals in June before testing his long-term foot problem against Andy Murray and most recently Denis Shapovalov.

However, the 35-year-old's plans to feature in the Melbourne ATP 250 ahead of the Australian Open in early January have suffered a setback after he tested positive for COVID-19 upon landing in his home country on Monday.

Nadal revealed the news on Twitter as he posted: "I wanted to announce that on my return home after playing the Abu Dhabi tournament, I have tested positive for COVID in the PCR test that was performed on me when I arrived in Spain.

"Both in Kuwait and Abu Dhabi we passed controls every two days and all were negative, the last being on Friday and having the results on Saturday.

"I am having some unpleasant moments but I hope that I will improve little by little. I am now homebound and have reported the result to those who have been in contact with me.

"As a consequence of the situation, I have to have total flexibility with my calendar and I will analyse my options. I will keep you informed of any decisions about my future tournaments!"

Nadal was eyeing the Australian Open, which starts on January 17, as his first major comeback, though he earlier admitted his entry was not guaranteed as he evaluated his foot injury and physical fitness.

"I cannot guarantee Australia one hundred per cent, because I need to go home and see how the body responds after these days," Nadal told reporters on Saturday. 

"I have time to make a decision. At this point in my career, I need to go day by day, study each movement well.

"I have been able to show a competitive level against good players even without being in perfect condition. There are things to improve but looking at things with perspective it has been a positive tournament [in Abu Dhabi].

"The main objective is to be healthy enough to do the things that I need to do and aspire to the objectives that I have always had. The illusion and passion continue to exist."

The ATP Tour event in Melbourne, which would be Nadal's first such tournament since August, is due to start on January 3.

Dominic Thiem will skip the Australian Open if he is not happy with his fitness at the end of December, the former US Open champion said on Sunday.

The 28-year-old has not played on the ATP Tour since suffering a wrist injury at the grass-court Mallorca Championships in June.

Thiem missed Wimbledon and could not defend his grand slam title at Flushing Meadows, with injury fears lingering ahead of the new season.

Despite not requiring surgery on the damaged wrist, Thiem has been unable to play competitively and experienced a fresh setback this month when he pulled out of the Mubadala World Tennis Championship, an exhibition event in Abu Dhabi.

In announcing that decision on December 14, Thiem said he was "not yet ready to compete at the highest level", and there was little to inspire confidence when he issued an update confirming he would not travel to play in two events ahead of the Australian Open.

Although Thiem still wants to play at Melbourne Park, where the slam begins on January 17, his prospects are hinging on him feeling significantly more optimistic about his game and fitness in a matter of days.

Thiem wrote: "After speaking to my team, we have decided to return to Austria, instead of flying directly to Australia.

"Unfortunately, I caught a cold [and tested negative for COVID-19] while in Dubai and was unable to practise last week. I will therefore not be in the physical condition required to be able to play the ATP Cup and Sydney ATP 250.

"After not competing for the last six months I can't take the risk of coming back too soon and picking up a further injury.

"Overall, the time I spent in Dubai was great as I've increased the intensity and level of practise and my wrist is almost at 100 per cent.

"My aim is still to play the Australian Open but we will make a final decision about my participation by the end of December."

World number four Karolina Pliskova has withdrawn from the upcoming Australian Open, succumbing to a hand injury.

Pliskova – a two-time grand slam runner-up and 2019 Australian Open semi-finalist – hurt her hand in a practice session.

The 16-time WTA Tour champion will miss the main draw of the year's opening slam event, which gets underway on January 17, for the first time since failing to progress beyond qualifying in 2012.

"Unfortunately I hurt my right hand in practice yesterday and I won't be able to play in Adelaide, Sydney and Australian Open this year," Czech star Pliskova said.

"I am sad not being able to start my season in Australia and I will miss my Australian fans very much."

Australian Open officials also confirmed Pliskova's absence on Thursday.

"You will be missed, @KaPliskova. Wishing you a speedy recovery," the Australian Open wrote via social media.

Pliskova lost in the Australian Open third round at Melbourne Park earlier this year before falling at the second hurdle at the French Open.

The 29-year-old then reached the Wimbledon decider, trumped by world number one Ash Barty, followed by a quarter-final appearance at the US Open.

Dominic Thiem's comeback has been further delayed as the 2020 US Open champion does not feel ready to return at this week's Mubadala World Tennis Championship.

Austrian star Thiem has been out of action since suffering a wrist injury at the Mallorca Championships in June.

The 28-year-old missed Wimbledon and was unable to defend his title at Flushing Meadows, but he appeared to be on course to make his comeback before the end of 2021 after revealing in October he does not require surgery on his wrist.

However, the world number 15 is now facing a battle to be back to full fitness for January's Australian Open after withdrawing from an exhibition event in Abu Dhabi.

"I was looking forward to making my return to competition at Abu Dhabi but I feel that I am not yet ready to compete at the highest level," the 17-time ATP Tour champion posted via Twitter on Tuesday.

"It's disappointing to not take part this year but I need to continue my preparation for the upcoming season."

Thiem follows Casper Ruud in pulling out of the tournament, which begins on Thursday, while Emma Raducanu is out of the women's singles after testing positive for coronavirus.

Dan Evans and Taylor Fritz have taken the places of former world number three Thiem and Ruud, joining Andrey Rublev, Denis Shapovalov, Andy Murray and defending champion Rafael Nadal in the draw.

Rafael Nadal is set to start his 2022 season at the Melbourne ATP 250 ahead of the Australian Open.

Nadal this week appeared on the entry list for the first grand slam of the year, which begins on January 17.

The Spaniard has not featured on the ATP Tour since August, when he lost against Lloyd Harris at the Citi Open in Washington D.C.

But Nadal is going to be back into the swing of things in the next month. The Melbourne 250 starts on January 4 and will serve as a warm-up for the Australian Open.

Gael Monfils is headlining the ATP 250 event in Adelaide during the same week, while Novak Djokovic – whose participation at the Australian Open is as of yet unclear, although he is also listed for entry – is set to lead Serbia at the ATP Cup in Sydney. 

Djokovic has not yet revealed his COVID-19 vaccination status. If he is not fully vaccinated, the 34-year-old may not be able to compete in Melbourne, barring a medical exemption.

Nadal has dropped down to world number six after another injury-hit season, in which he won two titles, triumphing in Barcelona and Rome.

He has only won the Australian Open once, in 2009, but has since been beaten four times in the final, in 2012, 2014, 2017 and 2019.

Since the start of the 2020 season, Nadal has played in four finals, winning them all, including last year's delayed French Open.

Serena Williams has withdrawn from the Australian Open as she is not yet ready to make a comeback from injury.

Williams has not played since suffering a torn hamstring at Wimbledon in June.

The 40-year-old stated last month that she was "better" and planned to play in the first grand slam of 2022 at Melbourne Park.

Williams will not go in search of a record-equalling 24th major title next month, though, revealing she is not fit enough to take her place in the draw.

She said in a statement: "Following the advice of my medical team, I have decided to withdraw from this year's Australian Open. While this is never an easy decision to make, I am not where I need to be physically to compete. 

"Melbourne  is one of my favourite cities to visit and I look forward to playing at the AO every year. I will miss seeing the fans but am excited to return and compete at my highest level."

The legendary American's last grand slam triumph came at the Australian Open in 2017.

While Williams will not compete, world number one Ash Barty will participate, as will US Open champion Emma Raducanu and four-time grand slam winner Naomi Osaka.

Novak Djokovic has been included in the official entry list for the 2022 Australian Open, with Tennis Australia adamant that no loopholes are being explored.

The world number one, who has won nine of his 20 grand slam titles in Melbourne, has not yet disclosed his COVID-19 vaccination status, meaning there is doubt over whether he will be able to participate.

Every person competing or attending the grand slam next month will need to have been fully vaccinated against coronavirus.

However, despite the uncertainty, the 34-year-old was named in the official list of players for the tournament draw.

Djokovic had already been named in Serbia's team for the ATP Cup, which is to be held in Sydney, leading to speculation that he could enter Australia by travelling directly to New South Wales, which has different COVID-19 restrictions to the state of Victoria, and may then seek a medical exemption to get around the rules applying to unvaccinated travellers.

James Merlino, Victoria's deputy premier, responded to these reports, which also suggested Djokovic had the backing of Tennis Australia.

"My view on this is really clear and really simple," Merlino said on Wednesday. "Everyone's looking forward to the Australian Open and everyone who will attend – spectators, players, officials, staff – everyone is expected to be fully vaccinated.

"They're the rules. Medical exemptions are just that – it's not a loophole for privileged tennis players. It is a medical exemption in exceptional circumstances if you have an acute medical condition."

Tennis Australia responded to Merlino's comments with a statement of their own.

"Any suggestion that Tennis Australia is seeking 'loopholes' within this process is simply untrue. Adjudicating on medical exemptions is the domain of independent medical experts. We are not in a position to influence this process and nor would we," the statement read.

"Any application for a medical exemption must follow strict government guidelines based on ATAGI (Australian Technical Advisory Group on Immunisation) clinical advice. This is the same process that applies to any person wanting to enter Australia."

While Djokovic's participation is unclear, Serena Williams is a big-name absentee. The 40-year-old, who is one shy of matching Margaret Court's record tally of 23 grand slams, had been expected to play in Melbourne.

Roger Federer had already confirmed his absence, but Rafael Nadal is set to compete for the first time since August.

World number two and US Open champion Daniil Medvedev takes his place in the draw, as does 2020 Australian Open finalist Dominic Thiem.

Australian world number one Ash Barty headlines the women's field, with Naomi Osaka, US Open winner Emma Raducanu and WTA Finals champion Garbine Muguruza also in the draw.

Bianca Andreescu, the 2019 US Open champion, has decided to skip the event to focus on her mental wellbeing.

World number one Novak Djokovic has committed to playing the ATP Cup in Sydney amid ongoing uncertainty over his title defence at next month's Australian Open.

Djokovic has been unwilling to confirm his place at January's Australia Open due to the COVID-19 mandate in Victoria.

The state of Victoria, where the year's opening grand slam takes place at Melbourne Park, has introduced a vaccine mandate for professional athletes and across most industries due to the coronavirus pandemic.

Djokovic's father, Srdjan, said the nine-time Australian Open champion is unlikely to feature in Melbourne unless vaccination rules are relaxed.

But in a boost for the slam's organisers, Djokovic was named in top-seeded Serbia's team for the third edition of the ATP Cup, which will take place in Sydney from January 1-9.

"We're excited to host the third edition of the ATP Cup in Sydney in 2022," said ATP Cup tournament director Tom Larner.

"The playing group enjoy representing their countries and to see 18 of the world’s Top 20 players commit to the event is testament to that.

"The event shows off the passion the playing group have for this format and we look forward to welcoming all 16 teams to Sydney later this month."

The 2021 Australian Open went ahead, albeit in February instead of January, and without fans for most of the tournament following a snap lockdown of Melbourne due to COVID-19.

Djokovic – winner of a joint-record 20 grand slam titles – was among the players critical of the conditions athletes endured prior to this year's Australian Open, with strict quarantine measures introduced.

Bianca Andreescu will miss the 2022 Australian Open to focus on her mental health after suffering a "very challenging" couple of years.

Andreescu has struggled with physical and mental concerns since winning the US Open two years ago.

The 21-year-old has felt the strain even more this year, with her grandmother in intensive care after contracting COVID-19, Andreescu also testing positive and spending significant time in isolation.

The former world number four has decided to skip the first grand slam next year as she takes extra time out to "reset, recover and grow", but vowed to return "stronger than ever."

The Canadian tweeted: "As you all know, the past two years have been very challenging for me for a variety of reasons.

"Especially this year in particular, I spent multiple weeks in isolation quarantining which affected me greatly – both mentally and physically. In addition, my grandmother spent several weeks in the ICU due to a covid infection, something that really hit me hard.

"A lot of days, I did not feel like myself, especially while I was training and/or playing matches. I felt like I was carrying the world on my shoulders.

"I could not detach myself from everything that was going on off the court; was feeling the collective sadness and turmoil around it and it took its toll on me.

"I want to give myself extra time to reset, recover and grow from this (as cliche [sic] as that sounds) and continue to inspire by doing charity work, giving back and working on myself because I know by doing this, I will come back stronger than ever.

"I will therefore not start my season in Australia this year, but will take some additional time to reflect, train and be ready for the upcoming 2022 season."

Novak Djokovic is unlikely to play at the Australian Open in January unless COVID-19 vaccination rules are relaxed, according to the player's father.

Organisers recently confirmed that players must be vaccinated against coronavirus to compete in the tournament, which begins on January 17.

World number one Djokovic, who won a record ninth title in Melbourne last year, has not publicly stated whether he has had the jab.

Srdjan Djokovic told Serbia's TV Prva that being vaccinated is a personal choice, and that Tennis Australia's rules are essentially "blackmail".

"As far as vaccines and non-vaccines are concerned, it is the personal right of each of us whether we will be vaccinated or not," he was quoted as saying by news website B92.

"No one has the right to enter into our intimacy, it is guaranteed by the constitution. Everyone has the right to decide on their health.

"Whether [Novak] is vaccinated or not, that is his exclusive right. Will he publish it, I don't think so. I don't know that decision either, and if I did, I wouldn't share it with you. He has the right to decide as he wants."

When asked about Djokovic's decision to play in Australia, his father added: "Whether he will appear there depends on how [the organisers] position themselves. He would want it with all his heart because he's an athlete, and we would love that too.

"Under these blackmails and conditions, he probably won't. I wouldn't do that. And he's my son, so you decide for yourself."

Djokovic, who is tied on 20 major singles titles with Rafael Nadal and Roger Federer, recently said he was unsure of his participation following his appearance at the ATP Finals in Turin.

"I was just waiting to hear what the news is going to be and now that I know we'll just have to wait and see," he said.

Ash Barty has announced her engagement to Liverpool fan and golfer Garry Kissick, capping a memorable year in style.

Barty added another sparkler to her collection when she revealed an engagement ring on Tuesday, having already landed the glistening Wimbledon trophy and an Olympic medal in the 2021 season.

She posted a picture of herself and Kissick on Instagram, showing off her ring and captioning the shot "Future Husband".

Kissick is a trainee professional at Brookwater Golf Club, a venue close to Brisbane, and is often seen in a Liverpool Football Club shirt, as was the case with the engagement picture.

He and Barty have visited Liverpool's home ground of Anfield together.

Speaking about having the likes of Kissick and coach Craig Tyzzer with her on the road, Barty said during her run to the Wimbledon title in July: "It's nice to be able to share some of these awesome moments with those that put so much time and energy into my career and allow me, encourage me, help me kind of work and figure out a plan and a way that they try and achieve our dreams. I think being able to share that with them is really special."

Barty won a bronze in mixed doubles at Tokyo 2020 alongside long-time friend John Peers, describing that achievement as "a dream come true".

She also won the Yarra Valley Classic, the Stuttgart Open, and WTA 1000 titles at Miami and Cincinnati before calling time on her season after a third-round exit from the US Open, where she lost to Shelby Rogers.

Barty finished the season as world number one for a third successive year, despite her recent inactivity.

She said a major triumph in her homeland was a priority for 2022, saying: "My focus is now on the Australian summer and doing everything I can to win the Australian Open. I can't wait to play at home again."