Quarterback is undoubtedly the most important position in football. Sustaining NFL success without stability at quarterback is a difficult proposition. This leads NFL teams to overvalue quarterbacks in the NFL draft and pay slightly above average or good quarterbacks like great ones.

There could be significant veteran quarterback movement in 2020. Here's a look at the passers that could be on the quarterback carousel in the offseason. Dak Prescott has been excluded because he isn't going anywhere. If a long term deal isn't worked out, the Cowboys are going to designate him as a franchise player in early March. Drew Brees has also been omitted. Although Brees has an expiring contract, he has made it clear that he is going to end his career with the Saints.

Tom Brady

Whether Brady is back with the Patriots for a 21st year will largely be his choice because of the way his contract is structured. In August, Brady received an $8 million raise for the 2019 season to $23 million. Included for salary cap purposes: Two contract years for 2020 and 2021 automatically voiding on the last day of the 2019 league year (March 18), so Brady's fully guaranteed $20.25 million roster bonus could be prorated over three years instead of just 2019. The renegotiated contract also contains a clause prohibiting the Patriots from designating Brady as a franchise or transition player in 2020. The voiding years and tag prohibition were borrowed from Brees' last couple of deals with the Saints.

There isn't anything the Patriots can do if Brady is set on testing free agency. Brady putting his Boston area home on the market has led to plenty of speculation that the 42-year-old would prefer a change of scenery for the final chapter of his long and illustrious NFL career.

Cam Newton

Kyle Allen got off to a hot start replacing an injured Newton, who is out for the season because of a Lisfranc foot injury, with the Panthers going 4-0. It made Newton's departure from Carolina in the offseason a foregone conclusion to many. Allen's last four games have been a different story. He's thrown nine interceptions while suffering three losses.

The Panthers were 0-2 when a struggling Newton decided it was better to let his foot heal instead of trying to play through it like he did last season with a shoulder injury. Newton was performing at a Pro Bowl level in 2018 when he hurt his right shoulder, which required offseason surgery to repair a partially torn rotator cuff. During the first half of last season, Newton completed 67.3 percent of his passes (177 of 263 attempts) with 15 touchdowns and four interceptions to post a 100.8 passer rating while leading Carolina to a 6-2 record. The 2015 NFL MVP was shut down for the final two games last season after it became apparent the shoulder injury had limited his ability to throw the football down the field. The Panthers lost the last six games Newton played in 2018.

Panthers owner David Tepper has been leery about paying Newton what it would take to keep him around beyond his current contract, which expires after the 2020 season. Newton will probably be looking for in excess of $30 million per year and $100 million in guarantees, where at least $65 million is fully guaranteed at signing on his next contract despite the recent injuries. The Panthers would pick up $19.1 million of 2020 cap room by dealing Newton in the offseason.

Philip Rivers

Going into the 2019 season, the assumption had been Rivers would be the Chargers' starting quarterback in 2020 despite him playing out his contract for the first time. This was before Rivers, who turns 38 in couple of weeks, starting looking like Father Time had caught up with him. His 14 interceptions, which include seven in the last two games, are the second most in the NFL. Rivers has already thrown more interceptions than he did in either of the 2017 and 2018 seasons.

Although the Chargers, who had Super Bowl aspirations when the season started, are a disappointing 4-7 with a struggling Rivers, head coach Anthony Lynn isn't considering a quarterback change. Rivers recently said he is going to regroup after the season to make sure he wants to continue playing in 2020. Even if Rivers is back in Los Angeles next season, it makes sense for the Chargers to come up with succession plan at quarterback.

Jameis Winston

Less than two weeks ago, Buccaneers head coach Bruce Arians told NBC Sports' Peter King that Winston had a really good chance to land a new contract if he could "keep things up." Winston was coming off two games, including a come-from-behind win over the Cardinals, where he threw for almost 700 yards while completing nearly 65 percent of his passes.

The 2015 first overall pick took a step backwards last Sunday against the Saints by throwing four interceptions, his third game this season with at least three picks. Winston has a league-leading 18 interceptions, which puts him on pace for 29. The only quarterback to throw that many interceptions in the last 30 years is Hall of Famer Brett Favre in 2005.

Winston played well enough down the stretch last year once he regained the starting job from Ryan Fitzpatrick after a midseason benching for the Buccaneers to give him a fifth year. Demonstrating that the Saints game was a minor hiccup seemingly would be enough reason to want Winston back for Arians, who has a reputation as a quarterback whisperer primarily because of his work with Peyton Manning early in his career, Ben Roethlisberger's ascension as an upper-echelon passer and for resurrecting Carson Palmer's career when he was with the Cardinals. That could either mean a short-term deal or even a non-exclusive franchise tag. This quarterback number is expected to be right around $27 million in 2020.

Teddy Bridgewater

Bridgewater has put himself in a position to be a starting quarterback next season. He thrived earlier this year while getting his first game action over an extended period of time since suffering a gruesome, career-threatening knee injury during the 2016 preseason when he was the Vikings starting quarterback. The Saints didn't really miss a beat in the five games he started because of Brees' thumb injury. In the five starts -- all victories -- Bridgewater completed 69.7 percent of his passes (115 of 165 attempts) for 1,205 yards with nine touchdowns and two interceptions, compiling a passer rating of 103.7.

Bridgewater was content to return to the Saints this season as the league's highest-paid backup quarterback despite the Dolphins pursuing him in free agency to be their starter. He felt staying in New Orleans was the better long-term option since he would have been just a stopgap quarterback in Miami. There has been some speculation that Brees, 40, could retire after the season, especially if the Saints win the Super Bowl. He hasn't given an indication either way on continuing to play but has acknowledged he is taking a year-by-year approach to his career.

Andy Dalton

Dalton had been Cincinnati's starting quarterback since being selected in second round of the 2011 NFL Draft before his benching eight games into the season. The winless Bengals wanted to take a look at 2019 fourth round pick Ryan Finley to see if he is the future at quarterback.

The only question is whether the Bengals will trade or release Dalton in the offseason. Dalton is scheduled to make $17.7 million in 2020, which is the final year of his contract. That's the amount of cap relief the Bengals will get next year by moving on from him.

Joe Flacco

The Broncos gave up a 2019 fourth round pick in March to acquire Flacco from the Ravens. He wasn't faring any better than Case Keenum did last season when Flacco suffered a season ending neck injury against the Colts in Week 8. The Broncos dealt Keenum, their 2018 starting quarterback, to the Redskins in March after just one lackluster season in Denver.

Flacco is under contract through the 2021 season with a $20.25 million salary in 2020. It would have been more advantageous financially for the Broncos to part ways with Flacco next year if his contract hadn't been restructured for salary cap purposes at the end of the preseason. Since $17 million of his salary was converted to signing bonus and two voiding contract years were added, the Broncos will have a $13.6 million cap charge by trading or releasing Flacco in the offseason. The Broncos would have been able to pick up $20.25 million of cap room by getting rid of Flacco in 2020 rather than $10.05 million had his contract been left alone.

Nick Foles

The Jaguars signed Foles to a four-year, $88 million contract with $50.125 million of guarantees in free agency to try to recapture the 2017 season success, which culminated in an AFC Championship Game appearance. Incentives make his deal worth as much as $102 million.

Foles broke his left clavicle in the first half of the season opener against the Chiefs. When eligible to return to action from injured reserve last week, Foles was given his starting job back, although 2019 sixth round pick Gardner Minshew had been performing capably during his absence. The promising young rookie gives the Jaguars quarterback flexibility. The most logical way Foles would depart Jacksonville after the season is in a trade considering his $15.125 million 2020 base salary was fully guaranteed when he signed his contract.

Ryan Tannehill

The Titans don't have a quarterback under contract for next season. Tannehill has been a major upgrade over 2015 second overall pick Marcus Mariota, who was benched for ineffectiveness. The Titans are 3-1 with Tannehill at starter and back in the AFC South race. Since taking over for Mariota, Tannehill is completing 70 percent of his passes for 1,017 yards with eight touchdowns and three interceptions to post a 107.5 passer rating.

The Titans' success with Tannehill is making it more difficult to be in a position to select a potential franchise quarterback in the first round of the 2020 NFL Draft. Tannehill may not be the answer but could be brought back until a long-term solution at quarterback is found. Since the Titans are comfortable paying Mariota $20.922 million this season on his fifth year option, there shouldn't be an issue with Tannehill making at least that much in 2020 to return as the starter.