NFL players under the microscope in 2019

Allen showed flashes in his rookie season but went just 5-6 in his starts, completing 52.8 percent of his passes. The expectations are much higher this season after the Bills made several big additions on offense, including wideouts John Brown and Cole Beasley.

Kansas City's defense underwent a huge makeover in the offseason after the team fell just short in the AFC championship game. Even an average defense could mean a Super Bowl for the Chiefs, considering how well the offense played with Patrick Mahomes under center last season. After moving on from Dee Ford and Justin Houston, the pressure will be on Clark to be a major disruptor.

The Jets signed Bell for big money after he held out from the Steelers for the entire 2018 season. Now is the time for Bell to prove that the holdout was worth it, as he hopes to transform the Jets offense under new head coach Adam Gase.

Brady continues to do things that are unprecedented, winning a Super Bowl at age 41 last season. No quarterback in NFL history has had success at age 42, but Brady hopes to buck the trend. It will be more difficult following Rob Gronkowski's retirement.

Brees is entering the final season of his contract and what could be the final year of his career at age 40. He completed an incredible 74.4 percent of his passes last season, but the Saints fell short in the NFC championship game due to a controversial pass interference no-call. Anything short of a Super Bowl will be a disappointment in New Orleans, but Brees will have to continue to perform.

Brown finally got out of Pittsburgh after a late-season controversy that saw him sit out Week 17. The grass isn't always greener, however, as Brown is joining a Raiders team that was non-competitive last season. Brown has produced a Hall of Fame resume with six consecutive 1,200 yard seasons, but it remains to be seen if he will replicate that in Oakland.

Minnesota signed Cousins last season to get over the hump after several seasons of mediocre passing offenses. Unfortunately, the Vikings regressed last season with Cousins under center, though the struggles certainly weren't all on him. The expectations are even higher this season after the Vikings failed to make the playoffs last year, and Cousins also must prove that he's more than the near-.500 quarterback he's been as a starter over the last four seasons.

All the attention was on Donald last year, but he answered the bell with a historic season that allowed him to win his third Defensive Player of the Year Award. Donald had a career-high 20.5 sacks and 25 tackles for loss in a truly dominant year, and it would be quite a feat if he could come close to those numbers for the second straight year. Once again, the Rams have gone all in with their offseason moves.

There's still plenty of time for Elliott and the Cowboys to come to a contract agreement, but early in camp it looks like the situation could get ugly. Jerry Jones has already sent a message via the media, and it remains to be seen if Elliott will be on the roster in Week 1. Given the Cowboys' lack of running back depth, they desperately need him.

The Dolphins had another offseason coaching change, with former Patriots defensive coach Brian Flores taking over. He doesn't have a great deal of talent to work with on defense, but Fitzpatrick looks like a keeper. The versatile defensive back could play either cornerback or safety and will likely be at the center of Flores' plans after a strong rookie season.

After five seasons of Blake Bortles, Jaguars fans were ready for a change. Former Super Bowl MVP Foles was a perfect match for the Jags during the offseason, and there are high expectations for Foles and the team's excellent young defense. Foles hasn't been a regular starter since he was with the Rams in 2015, and it remains to be seen how he will play with a lesser supporting cast.

Issues both on and off the field have hindered Fournette's career recently, and the Jaguars added a lot of depth behind him in the offseason. They still hope the former first-round pick is able to rebound after averaging only 3.3 yards per carry last season, and the offense's success could depend on Fournette getting back to his rookie level when he had more than 1,000 yards rushing.

After going 5-0 at the end of 2017, Garoppolo struggled last season before tearing his ACL in Week 3. San Francisco gave Garoppolo big money last year, and are hoping it will pay off with a competitive team this year. First, Garoppolo must stay healthy.

Gurley's health was a huge story late last season and into the offseason after he was diagnosed with an arthritic knee. The team re-signed Malcolm Brown and drafted Darrell Henderson in the third round as insurance for Gurley, who isn't expected to play in the preseason. His workload early in the regular season could be telling.

James certainly looked like a keeper in his rookie season, becoming an All-Pro after finishing with 105 tackles, three picks and 13 passes defensed. Already elite at his position, the Chargers are waiting anxiously for an encore.

Luck easily won Comeback Player of the Year after returning from a serious shoulder injury last season and leading the Colts to a 10-6 record. The expectations are much higher this season, especially after the team added even more weapons at wideout.

Mack joined the Bears just before Week 1 last year but wasted no time making an impact. There will be even more pressure on the pass rusher this season after defensive coordinator Vic Fangio departed for the Broncos head coaching job. Mack is one of the few players who has a realistic shot of beating out Aaron Donald for Defensive Player of the Year.

Mariota's future in Tennessee is up in the air after two subpar seasons. During that time he has just 24/23 TD/INT, and the Titans signed Ryan Tannehill to be a more formidable backup than what the team has had recently. While Tannehill isn't a threat to Mariota's job entering the season, the speculation could pick up if Mariota gets off to a slow start.

Mahomes took the NFL by storm in his first year as a starter, winning the MVP after throwing for more than 5,000 yards and 50 touchdowns. Most expect some regression from Mahomes, but the Chiefs have given him even more weapons after trading speedy Mecole Hardman in the second round of the draft.

The Browns won the offseason, particularly with their acquisition of star wideout Odell Beckham Jr. from the Giants. That puts more pressure on second-year quarterback Baker Mayfield after a strong rookie season, as Browns fans are now expecting the team to challenge in the AFC North. If the offense doesn't make big strides in 2019, it will likely be due to a lack of progress from Mayfield.

The Falcons defense took a huge step back last season, and it's no coincidence that Neal missed almost the entire year due to injury. The star safety made the Pro Bowl in 2017, and his absence was felt in every facet of the defense. Atlanta needs to take a step forward for head coach Dan Quinn to keep his job, and Neal is a big part of the team's plans.

The Panthers are coming off a disappointing season with a transitioning offense under coordinator Norv Turner. Newton was more accurate than ever with the new short passing game, but he floundered late in the year while nursing a shoulder injury that required surgery. Now at age 30, it remains to be seen if Newton will be able to run the ball as much as he has in past seasons.

The Steelers failed to make the playoffs last season, and some of the blame was put on Roethlisberger, who threw a league-high 16 interceptions. His job will likely be tougher this season after Pittsburgh traded Antonio Brown, and Big Ben is also getting older at age 37. if the team returns to the playoffs, it will likely be on Roethlisberger's shoulders.

Rosen looked like a deer in the headlights in his rookie season, playing on a really bad Cardinals team. The top opted to start over and draft Kyler Murray with the first pick this year  then trading Rosen to Miami. He's battling veteran Ryan Fitzpatrick for the starting job in a situation that isn't much better, but Rosen is out to prove the doubters wrong.

Stafford's stats regressed considerably last season, and the Lions finished 6-10 in head coach Matt Patricia's first season. The Lions are expected to run the ball more this season, but Stafford also needs to play better after averaging fewer than 7 yards per attempt for the first time since 2012.

Baltimore lost considerable talent on defense in the offseason but did add Thomas with a huge contract. Replacing Eric Weddle, the pressure is on Thomas to fill the void and also bounce back after playing only four games last year.

Coming off two injury-plagued seasons, Watt was the center of the Texans defense again last year with 16 sacks. The team has high hopes for a playoff run this season, but that will likely require another healthy campaign from Watt at age 30.

Wentz was well on his way to winning the MVP in 2017 after suffering a torn ACL late in the season, and the injury delayed the start of his 2018 campaign. He also missed time late last year due to a back injury. The difference in 2019 is that the Eagles don't have a great fallback plan if Wentz gets hurt again, as Nick Foles left in free agency. Philadelphia desperately needs Wentz to stay on the field and continue playing at a high level.

Wilson had another brilliant season in 2018, even with an offense that leaned on the run. The challenge this year is the loss of Doug Baldwin, who retired due to injury. After also losing Frank Clark on defense, there could be more pressure on Wilson to lead the Seahawks.

Winston has struggled over the last two seasons, and the Bucs hired head coach Bruce Arians to fix him. The former No. 1 overall draft choice is just 6-16 as the starter over the last two seasons, and Tampa Bay could move on from him if he doesn't improve this year.