Philosophical differences were behind the Houston Texans' decision to part with head coach David Culley after one season with the team, according to general manager Nick Caserio.

The Texans ended a disappointing campaign 4-13, and offensive coordinator Tim Kelly has also departed after eight years with the franchise, which finished third in the AFC South for a second consecutive season.

The Texans ended their season with a 28-25 loss to the Tennessee Titans, leading a late fightback against their rivals after finding themselves 21-0 down at the halfway point.

Caserio, who has been in the GM post for just a year, released a statement explaining the decision to relieve both Culley and Kelly of their duties, with the Texans ending the season ranked last in the NFL for total offense, and Culley having reportedly resisted attempts to make changes to his offensive staff. 

"Earlier today, I met with David Culley and Tim Kelly to inform them we will be moving in a different direction with the head coach and offensive coordinator positions," the statement read. "I came to this difficult but necessary decision after reviewing our football operations.

"While a change after one season is unusual, we had philosophical differences over the long-term direction and vision for our program moving forward. 

"We appreciate coach Culley for helping us navigate through a difficult season, but it is my responsibility to make decisions that I feel are best for our organisation.

"The search for the next coach of the Houston Texans will begin immediately."

The Arizona Cardinals continued their excellent road form as they edged the Dallas Cowboys 25-22 in a potential-playoff preview with Kyler Murray leading the way on Sunday.

The Cardinals improved their season record to 11-5 and their road record to 8-1, snapping a three-game skid, with Texas-born Murray throwing two touchdowns as he completed 26 of 38 attempts for 263 yards.

The Cowboys had trailed 22-7 at the final charge but stormed back into contention as Dak Prescott threw three TD passes for the game but Murray expertly managed the clock late.

Murray found Antoine Wesley for two TDs including a spectacular catch in the third quarter, while Jonathan Ward made a remarkable helmet catch on a fake punt.

The Cowboys lost Michael Gallup to injury upon his second-quarter receiving touchdown and did not return, not helping their cause.

Prescott, who completed 24 of 38 passes for 226 yards along with 20 rushing yards, found Cedrick Wilson and Amari Cooper for final-quarter TDs to tighten the game but he also had a costly fumble at 22-14.

Chargers snap skid as Williams scores 101-yard return

The Los Angeles Chargers snapped a two-game skid with a 34-13 victory over the Denver Broncos to boost their Wild Card hopes as they improve to a 9-7 record.

Chargers quarterback Justin Herbert threw 22 of 31 passes for 237 yards with two touchdowns, breaking the franchise record for single-season touchdown passes at 35.

Andre Williams scored a 101-yard kickoff return touchdown in the fourth quarter, while Austin Ekeler returned to LA's line-up and was important, with 17 carries for 58 yards and a touchdown, along with three receptions for 54 yards.

Lance leads 49ers to key win in Wild Card race

Trey Lance stepped in for the injured Jimmy Garoppolo and provided two touchdown passes as the San Francisco 49ers won 23-7 over the Houston Texans.

Lance completed 16 of 23 passes for 249 yards with the two TDs and an interception to help the 49ers improve to 9-7 in the NFC Wild Card pursuit.

Deebo Samuel and Elijah Mitchell scored the touchdowns as the 49ers scored 20 second-half points to secure the win.

Miami Dolphins general manager Chris Grier said the franchise did their "due diligence" regarding a trade for wantaway Houston Texans quarterback Deshaun Watson before opting not to make a deal.

The Dolphins were reportedly favourites to land Watson before Tuesday's NFL deadline as the three-time Pro Bowler was believed to have been willing to waive his no-trade clause.

It sparked uncertainty over the future of second-year QB Tua Tagovailoa, however, a trade for Watson did not materialise.

Grier was asked about Miami's interest in Watson – who is yet to play this season – on Wednesday and he told reporters midweek: "We never got to a point where anything was going to be realistic in terms of happening.

"It was still us just doing our due diligence, just talking through things. We never got to a point where anything was that close to happening."

Topping 4,000 yards for the second time in his career as he racked up 4,823 to lead the league, Watson threw for 33 touchdowns and seven interceptions last season.

Fifth in the NFL in air yards per attempt (9.27), according to Stats Perform data, Watson did an excellent job of balancing his aggression with smart decision-making.

Watson threw a pickable pass on just 2.28 per cent of his attempts, the fourth-lowest rate in the NFL last term.

This season, Tagovailoa has 103 completions for 1,040 yards, seven touchdowns and five interceptions in five games.

"I don't think it's any different than any player on the roster, honestly," Grier said. "Because if there's a player available around the league that's viewed as being one of the top players in the league at any position, I think you look at it and try to go for it.

"We're very happy with Tua. We think he's developing well. Brian has been very consistent with his message, and we have been as well.

"He's working hard, he's showing a lot of improvement and we think he'll continue to develop and be the player he should be."

Watson will remain in Houston until at least the end of the season and Texans GM Nick Caserio added: "The veracity of some of what has been reported is a little bit stretched. But that's just the nature of how these things work.

"There were various levels of discussions, specific to him and specific to other players as well. In the end, there was no trade that came to fruition, so I don't really have any comment about some of the logistics and the mechanics about what happened and what hasn't happened, what did happen."

Tyrod Taylor has been confirmed as the Houston Texans' starting quarterback for the 2021 NFL season. 

Taylor, who signed a one-year, $5.5million contract in Houston, was widely expected to be named the Texans' QB1 – a decision confirmed by head coach David Culley on Monday. 

The Texans, for whom third-round rookie Davis Mills will serve as back-up, are set for a testing year. 

Deshaun Watson has been the team's star QB over the past four seasons, last year leading the league in passing yards (4,823) and passing yards per attempt (8.87) – this despite being sacked 49 times, second only to Carson Wentz. 

Watson was the one bright spot on a team that finished 4-12 in 2020, but he is not likely to feature this season despite remaining on the roster. 

The 25-year-old in January asked for a trade, only for talk of a move to be overshadowed two months later by the emergence of sexual assault and misconduct allegations. Watson is the subject of investigations from the police and the NFL and faces 22 civil lawsuits. 

Watson has not been restricted from taking part in team activities, yet a belated exit is anticipated after a period on the sidelines. 

That leaves Taylor in the firing line on a team forecast to have the worst record in the league. 

The 32-year-old was a regular for the Bills for three years between 2015 and 2017, but he has started only four games in three seasons since leaving Buffalo – three with the Cleveland Browns in 2018 and one last year with the Los Angeles Chargers. 

Taylor completed only 16 of his 30 pass attempts in 2020, a small sample size providing a 53.3 completion percentage that paled next to Watson's 70.2. 

The Texans start against the Jacksonville Jaguars and number one overall pick Trevor Lawrence on Sunday.