Andy Murray believes Carlos Alcaraz can be a dominant figure in tennis "for as long as he wants" but cautioned against expecting him to challenge the grand slam records of the Big Three.

Roger Federer's haul of 20 slam titles has been overtaken by Rafael Nadal and Novak Djokovic, who both have 22 majors, but those three are streets ahead of every other men's singles player in history.

Next on the list is Pete Sampras with 14 slams, which was itself a total that many once fancied would not be beaten for decades.

Murray was for a time part of a Big Four, until he got left behind by the relentless winning of his three great rivals. Federer has retired, but Djokovic and Nadal may yet have more slam titles in them.

At the age of 19, Alcaraz is already off the mark, winning the US Open last year, and he has jumped back to world number one after winning the Indian Wells Open on Sunday.

Djokovic and Nadal will be big threats to Alcaraz's hopes of triumphing at the French Open, but the young Spaniard is no longer simply the coming player on the ATP. He has arrived, and Murray is convinced Alcaraz is the real deal and poised to stay at the top of the sport for years to come.

"He has an excellent game, an all-around game that I think will translate well onto all surfaces," Murray said.

"He's not the biggest guy, but he can serve big. He's an unbelievable mover, great athlete. Has a lot of variety in his game. Takes the ball on a lot. That's something that you hope that he keeps.

"I know from experience that it's a bit easier playing that way when you're sort of 18, 19, and there's not any scar tissue there. I hope that he maintains that style of play because it's exciting to watch."

The prediction that Alcaraz can be an all-court player, and therefore succeed on grass as well as the hard and clay courts where he has already found success, bodes well for his prospects of stacking up slams.

Murray might have faced Alcaraz in round three at the Miami Open this fortnight, but the veteran Briton, a three-time slam winner and former number one, lost his opener on Wednesday to Serbian Dusan Lajovic.

There have only been two matches on tour between Alcaraz and Murray to date, both coming in the 2021 season when they won one each.

Alcaraz is the defending champion in Miami, and a clear favourite after crushing Daniil Medvedev in the Indian Wells title match. He brings a 14-1 record for the year into the tournament.

"He's obviously so far in his young career doing better than most of the guys that have come in the last eight to 10 years," Murray said.

"I know a lot of people are expecting everyone to win 20-plus grand slams now, like that's sort of normal. I wouldn't predict that for anyone.

"I would imagine he would be right at the top of the game for, well, as long as he wants to play."

Novak Djokovic has been ruled out of the Miami Open after tournament organisers "exhausted all the options" in an effort to secure him a travel exemption.

The 22-time grand slam winner withdrew from the Indian Wells Open as he is unable to play in the United States.

He is not vaccinated against COVID-19, which remains a requirement of international travellers, but Djokovic had hoped to be granted special permission to enter the country.

US tennis authorities and a number of politicians also expressed support for an exception being made for the 35-year-old Djokovic, with US president Joe Biden urged to reconsider policy.

Even last week, Serbian superstar Djokovic was clinging to hopes of playing the Miami Open, which he has won six times.

However, tournament director James Blake told Tennis Channel there is no chance of that happening, despite extensive efforts.

"Obviously, we're one of the premier tournaments in the world, we'd like to have the best players that can play," said Blake, a former world number four.

"We did all that we could. We tried to talk to the government, but that's out of our hands. We tried and he wasn't able to play."

Blake said he was in the same position as Indian Wells tournament director Tommy Haas, being unable to influence government-level decisions.

"We tried to get Novak Djokovic to be allowed to get an exemption, but that wasn't able to happen," Blake said. "We'd love to have him, and he’s our greatest champion, won it six times here.

"Unfortunately, that's way above my pay grade."

Blake added: "We exhausted all the options we knew of. Hopefully Novak will be back this year and hopefully he will be back for all the later events in the States including Cincinnati and the US Open."

Jannik Sinner followed in the footsteps of three all-time tennis greats as he became the fourth teenager in history to reach a men's singles final at the Miami Open.

The 19-year-old Italian hit three huge backhand winners to break serve in the final game as he pulled off a 5-7 6-4 6-4 victory over Spain's Roberto Bautista Agut in their last-four clash.

It means Sinner matches Andre Agassi, Rafael Nadal and Novak Djokovic - players who went on to be ranked number one in the world - in becoming a finalist at the Masters 1000 tournament while still in his teens.

The hotly tipped world number 31 will contest a final at this level for the first time in his career on Sunday, awaiting the winner of the second semi-final between Andrey Rublev and Hubert Hurkacz.

Sinner said of his feat: "It sounds incredible. I'm very, very happy about today because obviously being the first semi-final it's not easy to play, especially on a Masters event, and playing against a very, very solid player in Roberto.

"We had a tough battle two weeks ago, and coming out as a winner today it means a lot to me."

Sinner also won that previous match, another tight three-setter, in Dubai.

Speaking on Amazon Prime, he explained how he recovered from a slow start to win the Miami tussle.

"In the beginning I think we were both a little bit tight and then we both played a little bit better," Sinner said.

"Today was not easy, it was a little bit windy, and in the end I tried to serve better and try to move him a little bit more, try to mix it up a little bit, and that was the key today.

"He was serving a few second serves in the last game and I just tried to go for it and even if I lost the game I was 5-5, so I was up in the score and it was the right decision."

Agassi, in 1990, and Djokovic, in 2007, were both teenage champions at the event, beating Stefan Edberg and Guillermo Canas respectively in the title matches.

Nadal lost to Roger Federer in the 2005 final, with the Swiss coming from two sets down to win what was then a five-set finale to the tournament. It has since gone back to being a best-of-three match.

Sinner may have benefited from Nadal, Djokovic and Federer electing to skip this year's tournament, but many believe he has the potential to follow them to the very top of the game.

Former women's world number five Daniela Hantuchova hailed Sinner's "braveness and calmness", adding: "When it really mattered, he stepped it up big time and to be able to do that at such a young age, we are looking at something very, very special here."

Greg Rusedski, runner-up at the 1997 US Open, added on Amazon's broadcast: "Rafa was the youngest to be in the Miami finals. Mentally they have a lot in common. Different styles but just bold and brave."

Second seed Stefanos Tsitsipas has blown a strong position to be knocked out of the Miami Open by world number 37 Hubert Hurkacz in three sets on Thursday night.

The Polish 26th seed lost the first set and trailed 0-2 in the second with Tsitsipas having two break points, before fighting back for an outstanding 2-6 6-3 6-4 triumph.

The victory seals Hurkacz's place in his first-ever Masters 1000 semi-final where he will face Russian fourth seed Andrey Rublev.

On Thursday night, Rublev won 7-5 7-6 (9-7) over Sebastian Korda, ending the young American's exceptional run in Miami.

Tsitsipas's demise was the major story on Thursday, having only dropped one set in his previous three matches in Miami.

The Greek world number five was in form, having made February's Australian Open semi-finals and last week's Mexican Open final.

Tsitsipas was in control until Hurkacz dialed up his aggression in the second, producing a brilliant flick after the Greek's volley to take advantage at 2-2.

Hurkacz got the crucial break at 2-2 in the third when the Greek coughed up a mistake by missing a routine smash.

The 24-year-old Pole also sent down 15 aces in a breakthrough win.

"It is so big," Hurkacz said in his on-court interview about reaching his maiden Masters 1000 semi-final.

"I was trying to keep fighting and that’s what I did. [I am] super pumped and happy that I was able to turn this match around.

"He was returning very well and I had to play a lot of rallies. At the beginning of the match, I tried to go for too much, so then I was trying to adapt my game a little bit."

Rublev claimed his 20th ATP Tour win for the calendar year, the most of any player ahead of Daniil Medvedev and Tsitsipas with 17, to book his semi-final spot against Hurkacz.

The defeat ended 20-year-old Florida resident Korda's superb run, where he claimed his first top 20 win against Fabio Fognini and first top 10 victory against Diego Schwartzman.

Top seed Daniil Medvedev powered his way into the Miami Open quarter-finals, along with Stefanos Tsitsipas and Andrey Rublev on Tuesday.

Medvedev won in straight sets against unseeded American Frances Tiafoe, hitting 24 winners.

Second seed Stefanos Tsitsipas won in straight sets against 24th seed Lorenzo Sonego, although the second went to a tie-break which the Greek dominated.

World number eight Andrey Rublev got past Marin Cilic in straight sets to book his last-eight spot.

Fifth seed Diego Schwartzman was the major casualty on Tuesday, losing to unseeded American Sebastian Korda in three sets. Seeds Josh Isner, Milos Raonic and Taylor Fritz also exited.

TOP SEED EASES INTO LAST EIGHT

World number two Medvedev was too good for Tiafoe in a 6-4 6-3 victory.

Medvedev improved his 2021 record to 17-2, sending down 11 aces with a dominant first-serve display while taking three of his four break points.

The 2021 Australian Open runner-up will meet seventh seed Roberto Bautista Agut in his maiden Miami Open quarter-finals appearance.

"It was definitely a tough match," the Russian said in his post-match on-court interview. "I am just looking forward to tomorrow. Roberto is a hell of a player.

"I feel like sometimes, when I have practised with him and played against him, that his ranking should be higher. There are reasons why it is not and I am going to try to do something with it tomorrow."

STEFANOS SIZZLES PAST SONEGO

Tsitsipas kept up his good form after making last month's Australian Open semi-finals, by booking his first Miami Open quarter-final appearance.

The Greek world number five defeated Sonego 6-2 7-6 (7-2) with a clinical performance to keep alive his dream of a maiden ATP Masters title.

Tsitsipas won in just over an hour and a half, proving too good on serve, having not offered up one break point and winning 89 per cent of first-serve points.

He was also too good with his return for the Italian, winning 35 per cent of the points on Sonego's serve.

The Greek will take on Polish 26th seed Hubert Hurkacz in the last eight, after he knocked out 12th seed Raonic 4-6 6-3 7-6 (7-4).

FIFTH SEED TOPPLED BY KORDA

World number nine Schwartzman was knocked out in three sets by Korda 6-3 4-6 7-5 as he continues his super run.

Florida resident Korda, 20, reached his maiden ATP 1000 quarter-final, showing fight after the Argentinian raised his game in the second set, winning after an early break in the last.

Rublev made light work of former US Open champion Marin Cilic, triumphing 6-4 6-4.

Bautista Agut got past 18th seed Isner 6-3 4-6 7-6 (9-7), while Jannik Sinner defeated Alexander Zverev's conqueror Emil Ruusuvuori 6-3 6-2.

Alexander Bublik, seeded 32nd, sent down 23 aces as he beat Taylor Fritz 6-7 (5-7) 6-3 6-4.

Stefanos Tsitsipas battled through to the Miami Open round of 16 and he was joined by Andrey Rublev on Monday.

Greek star and second seed Tsitsipas got the better of 2014 US Open runner-up Kei Nishikori in Miami.

Rublev continued his fine 2021 with a straight-sets demolition of Marton Fucsovics at the ATP 1000 tournament.

In-form Aslan Karatsev, however, bowed out following a surprise loss to Sebastian Korda.

TSITSIPAS HALTS NISHIKORI

Despite a mid-match wobble, Tsitsipas overcame Nishikori 6-3 3-6 6-1 to reach the fourth round.

Former world number four Nishikori forced a deciding set but Tsitsipas withstood the Japanese's comeback.

Tsitsipas, who hit 32 winners, will meet Lorenzo Sonego for a place in the quarter-finals after the 24th seed defeated Daniel Elahi Galan 7-6 (8-6) 6-3.

RUBLEV STAYS HOT

Russian fourth seed Rublev made light work of Fucsovics 6-2 6-1 in just 52 minutes.

Rublev leads the ATP Tour with 18 victories this season after eliminating the in-form Hungarian, ahead of top seed Daniil Medvedev (16-2).

The result secured a third win for Rublev over 29th seed Fucsovics this month.

"I was laughing, because of [the] situation and plus Marton also told me, 'I don't want to see you. I don't want to see you'," Rublev said, cracking a laugh. "[It was] just a situation that [was] fun, and I feel sorry."

Awaiting Rublev is 2014 US Open champion and former world number three Marin Cilic, who beat Lorenzo Musetti 6-3 6-4.

KARATSEV CONQUERED

For only the third time this year, Australian Open semi-finalist and Dubai Tennis Championships winner Karatsev tasted defeat following a 6-3 6-0 loss at the hands of Korda.

American sensation Korda became the first player outside the top five to beat Karatsev this year, with the latter's previous two losses coming against world number one Novak Djokovic and world number four Dominic Thiem.

"It is super special [to reach the Round of 16], especially playing a guy who was as hot as he was," said Korda. "I just took the tactics that I used [against him] at Roland Garros and it worked out really well today."

Diego Schwartzman stands in the way of Korda and the quarters after the fifth seed accounted for Adrian Mannarino 6-1 6-4.

Elsewhere, Denis Shapovalov – the sixth seed – was upstaged by Hubert Hurkacz 6-3 7-6 (8-6).

Another Canadian awaits Hurkacz after 12th seed Milos Raonic was a 6-4 7-5 winner against Ugo Humbert.

Stefanos Tsitsipas continued his strong run of form en route to the Miami Open third round, while Aslan Karatsev's maintained his fairytale run in 2021.

Greek star Tsitsipas flexed his muscles in a straight-sets win over Damir Dzumhur on Saturday.

Australian Open semi-finalist and Dubai Tennis Championships winner Karatsev enjoyed a victorious Miami debut.

Andrey Rublev, Diego Schwartzman, Denis Shapovalov, Marin Cilic and Milos Raonic also progressed at the ATP 1000 tournament.

TSITSIPAS STAYS HOT

World number five Tsitsipas eased past Dzumhur 6-1 6-4 in his first appearance since losing in last week's Mexican Open final.

Tsitsipas (15-4) became the third player to reach 15 wins this season, the second seed following in the footsteps of Russian duo Rublev (17-3) and Daniil Medvedev (15-2).

"It was a great match, especially against a guy that I probably don't have a good record playing against in the past," said Tsitsipas. "I started the match very strong, breaking him twice and taking a big lead in the score, and I think the things worked out by themselves after that."

Tsitsipas will face Kei Nishikori after the Japanese outlasted Aljaz Bedene 7-6 (8-6) 5-7 6-4.

NO STOPPING KARATSEV

Karatsev's Miami Open debut ended in a 6-4 6-3 win for the 17th-seeded Russian over Mikhail Kukushkin.

Already in the ATP's top 100 and set to keep climbing, Karatsev broke serve four times en route to the next round, where Sebastian Korda awaits after upstaging 10th seed Fabio Fognini 1-6 6-4 6-2.

"Of course it gives me confidence to win my first title, but you arrive here and it’s a different surface and new tournament," said Karatsev, who ended last season ranked 112th before bursting into the top 30 behind his semi-final run at Melbourne Park. "So you try [to think of it] as a new tournament and new place, but of course it gives me a lot of confidence."

Karatsev owns a 13-2 record this year, with his only two losses coming against world number one Novak Djokovic and US Open champion Dominic Thiem.

RUBLEV ROLLS ON

Fourth seed Rublev has proven to be remarkably consistent, highlighted by his crushing 6-1 6-2 rain-interrupted victory against Tennys Sandgren.

Having equalled his previous best run in Miami, Rublev will play 29th seed Marton Fucsovics who took down Thanasi Kokkinakis 7-6 (7-3) 6-7 (4-7) 6-4.

Rublev has won a Tour-leading 17 matches this year.

Elsewhere, fifth seed Schwartzman was a 6-3 6-3 winner against Yasutaka Uchiyama, Shapovalov – the sixth seed – trumped Ilya Ivashka 6-7 (5-7) 6-4 6-4 in a marathon, 12th seed Raonic accounted for Jordan Thompson 6-2 6-1, former US Open winner Cilic surprised 13th seed Christian Garin 3-6 7-5 7-6 (7-5), while 15th seed Alex de Minaur was eliminated.

Vasek Pospisil launched a stunning tirade during his three-set defeat to American qualifier Mackenzie McDonald in the first round of the Miami Open on Wednesday.

The Canadian former world number 25 was docked a point for verbal abuse, subsequently conceding the first set, before a meltdown during the change of ends.

Pospisil used a profanity in reference to ATP chairman Andrea Gaudenzi when speaking to chair umpire Arnaud Gabas.

“[Gaudenzi was] screaming at me in a player meeting for trying to unite the players — for an hour and a half," Pospisil said to Gabas. "If you want to default me, I’ll gladly sue this whole organisation.”

He did fight back to win the second set but ultimately lost to McDonald 6-3 4-6 6-3.

Pospisil, who is nowadays ranked 67th, was joined among the first-round exits by last week's Mexican Open semi-finalist Dominik Koepfer, who went down 6-1 6-4 to wildcard Hugo Gaston as he claimed his first career Masters 1000 win.

Sam Querrey, ranked 63rd, also bowed out 6-3 6-4 to Lu Yen-hsun, who will meet world number two Daniil Medvedev in the second round.

YOUNGSTER BEATS VETERAN

Australian youngster Alexei Popyrin secured his maiden win at the Miami Open, knocking out the oldest player in the draw Feliciano Lopez 6-4 7-6 (7-4).

Popyrin, 21, claimed his first ATP Tour title last month in Singapore and backed that up with a strong display against the 39-year-old former top 20 Spaniard.

Recent Open 13 Marseille runner-up Pierre-Hugues Herbert got past Portugal's Pedro Sousa 6-1 6-3, while South Africa's Lloyd Harris defeated Emilio Nava 6-4 7-6 (9-7).

Frances Tiafoe won in the final match of Wednesday, coming from behind to beat Stefano Travaglia 5-7 6-4 6-2.

COMEBACK CAM

Brit Cameron Norrie produced a heroic final-set fightback to claim his spot in the second round, where he will face Grigor Dimitrov.

Norrie trailed 5-1 in the third set against Yoshihito Nishioka, before winning 6-1 3-6 7-5, winning the last six games to clinch victory.

The 56th-ranked Brit sent down eight aces in the victory, although he got the edge on return and converted seven of his 10 break points.

SECOND ROUND

Top seed Medvedev will face Lu on Thursday, while third seed Alexander Zverev will take on Finland's Emil Ruusuvuori.

Norrie will meet Dimitrov, while 11th seed Felix Auger-Aliassime faces Herbert and eighth seed David Goffin will take on James Duckworth.

Harris has a match-up against seventh seed Roberto Bautista Agut.

Former world number one Andy Murray will compete at the Miami Open for the first time since 2016 after being granted a wildcard.

Murray has not played on the ATP Tour since last month's Rotterdam Open, where the three-time major champion lost to Andrey Rublev in the round of 16.

But Murray – who won the ATP 1000 event in 2009 and 2013 – is set to end his Miami absence, having undergone hip surgeries in 2018 and 2019.

"It's a city I love, and I've spent a lot of time here over the last 15 years, I feel comfortable," the 33-year-old, who sat out the Australian Open after testing positive for coronavirus, told PEOPLE Magazine.

"But over the next few months, I want to play matches — especially against the top players — work on my game and climb the rankings. I want to get back playing a sport I love."

Murray added: "The last few years has been really hard. After the operation, there were no guarantees I would play again, but I've been working very hard on my conditioning and over the last few months I've felt the best I have for years. 

"I'll need to be mindful of my schedule moving forward but I'm excited to be back competing — with a metal hip."

"But every match feels like progress and I'm learning from each one," he continued.

The Miami Open will get underway at Hard Rock Stadium on March 24 after the tournament was cancelled last year amid the COVID-19 pandemic.

"It is exciting to see Andy back in Miami," Miami Open Tournament Director James Blake said.

"As someone who has had to battle back from injuy during his career, I understand and respect all the hard work Andy has put in to get back on tour."