The Comeback Player of the Year is perhaps the most nebulous award in all the NFL. There don't seem to be any hard or fast rules dictating exactly WHAT a player has to be coming back from in order to win the prize. Returning from injury is usually a good way to attract the voters attention. In 2018, Andrew Luck passed for 4,593 yards and 39 touchdowns, enough to earn him the award after missing the entire 2017 campaign.

But Philip Rivers wasn't injured in 2012, as he led the San Diego Chargers to a 7-9 record on the back of his 3,606 yards and 26 touchdowns. But 4,478 yards and 32 touchdown passes were deemed enough of a comeback for him to take the trophy after the 2013 season. It is, as I say, rather ambiguous, and as such can have any number of viable candidates in the running.

Fanduel Sportsbook have opened a book on those in the running for the 2019 award. Here, we'll take a look at four of the favorites, while also offering thoughts on one long shot player who will certainly be looking for better form and fortune in 2019.

Jimmy Garoppolo, +400

Jimmy Garoppolo is an obvious candidate for a bounce-back season in 2019, after playing only three times a year ago. To be honest, he didn't look too great in his small sample size. Garoppolo completed less than 60% of his pass attempts in 2018, finding a receiver on 53 of his 89 pass attempts. He did average an impressive 8.1 yards per attempt, and his touchdown rate was a far from shabby 5.6%. But his interception rate was 3.4%, an increase on the 2.8% he posted in the last five games of the 2017 season.

Garoppolo was also far from impressive on a per play basis. According to numberFire's Passing Net Expected Points (NEP) per drop back metric, Garoppolo averaged 0.01 Passing Net Expected Points (NEP) per drop back, the 31st out of 43 quarterbacks with a minimum of 100 drop backs last season. That's not great, especially considering the San Francisco 49ers will be paying Garoppolo $19.35m this season.

There are question marks surrounding the players who will be assisting Garoppolo for the 49ers this season. Dante Pettis was a player many had high hopes for earlier this offseason, but recent reports suggest he needs to "compete" for his job. Our projections have Garoppolo passing for just over 4,000 yards and 23 touchdowns. These are decent numbers, but Garoppolo may need the 49ers to be very, very good in order to secure this award. Although it should be pointed out that 14 quarterbacks have won this award, so Garoppolo is going to be in the running just through the position he plays.

Le'Veon Bell, +400

Le'Veon Bell is the joint favorite to scoop the comeback player of the year award, after putting up career lows across all statistical categories in 2018. He didn't play a single game, of course, choosing to sit out the season after refusing to sign the franchise tag offer from the Pittsburgh Steelers. The last time we saw Bell, he was one of the most productive playmakers in the entire NFL. In 2017, Bell amassed 1,945 yards from scrimmage for the Steelers, one of three seasons in his career in which Bell has topped 1,800 yards in a season.

Things have changed since then, however. Bell is now a member of the New York Jets, coached by former Miami Dolphins boss Adam Gase. The Jets offensive line is not as good as that Bell enjoyed playing with in Pittsburgh, and Gase's history indicates that the Jets offense may not make a ton of plays on offense. The Dolphins ran the 11th fewest plays in 2017, and were dead last in 2018.

For Bell to be a serious contender, he probably needs to go way past the 1,500 yards from scrimmage mark. The Jets have had two players exceed this amount since the 2004 season, namely Thomas Jones (1,519 in 2008) and Brandon Marshall (1,502 in 2015). Our projections have him up around 1,700. But there is a danger that those numbers are hoping the 2017 Bell turns up, fit and ready to go. A year away from the game at Bell's age makes him a risky investment at his current odds.

Earl Thomas, +1400

The Comeback Player of the Year has been awarded to a defensive back once its history. The second player from this group could very well be former Seattle Seahawk and current Baltimore Ravens safety Earl Thomas.

Thomas has been named to six Pro Bowls during his NFL career, and been selected as an All-Pro three times. Injury restricted him to just four games last season, but he was off to a torrid start to what would end up being his last season with the Seahawks. Thomas intercepted three passes in his four games, after recording four interceptions in his previous 25 outings, as well as breaking up five passes.

Last season, the Ravens allowed the fewest yards in the entire NFL, with only five teams allowing more yards through the air than the 3,360 they gave up. On paper, adding Thomas to this mix would seem to be a case of the rich getting richer. However, several key players are now missing from the 20018 unit. The Ravens are banking on Thomas returning to his best form as soon as he pulls on his Ravens jersey. If he can, and recreates his enforcer role in the AFC North, then his name will be in the conversation for this prize.

Cam Newton, +1600

Carolina Panthers were 6-2 at one stage in 2018, with Cam Newton looking like he was really enjoying playing in a Norv Turner offense. By the end of the campaign, they had fallen to 7-9 and missed the postseason, thanks in no small part to Newton's shoulder injury hamstringing the whole offense.

Newton set career highs in completions (320) and completion percentage (67.9%), and finished with a 0.12 Passing NEP per drop back. This was 11th among the 18 quarterbacks with at least 500 drop backs. However, in the seasons first seven weeks, this figure was up at 0.14. Only once in his career had Newton managed to sustain an average higher than this over the course of a season, and that was back in his MVP campaign of 2015.

If Newton is able to stay healthy, and his young playmakers like D.J. Moore and Curtis Samuel are able to live up to all their hype, then Newton has a great chance of getting back to his MVP form. Especially if Newton is able to continue operating as one of the NFL's best goal line backs, then he should be a fantasy superstar and a player who enjoys a great bounce-back year.

Derek Carr, +4400

It may sound strange to expect a bounce-back from a player who set career highs in passing yards and yards per attempt, but that's where we are with Derek Carr. Carr eclipsed the 4,000 yard mark for the first time in 2018, finishing with 4,049 at 7.3 yards per attempt. However, Carr's inefficiency on a per play basis saw him finish near the bottom according to numberFire metrics. Only one QB had a lower Passing NEP per drop back average than Carr's 0.06 last season (minimum 500 drop backs).

Carr's touchdown rate of 3.4% was the lowest mark of his career, and Carr failed to throw for at least 20 scores in a season for the first time. But on paper, Carr has a lot more weapons at his disposal this time around. The Oakland Raiders added former Los Angeles Chargers speedster Tyrell Williams in free agency, and also acquired one of the best wide receivers of the 21st century in Antonio Brown from the Steelers. There is also first-round selection Josh Jacobs chipping in at running back, hopefully as an upgrade over Doug Martin. The Raiders offense has a good chance to propel them away from the NFL basement.

That is assuming, of course, that Brown's feet/helmet concerns/desire to create drama allow him to actually take to the field, and that he is able to reproduce the form he showed as a member of the Steelers. This is looking far from a guarantee, as I write this. But if Carr and Brown can form a productive partnership, and the Raiders are relevant again, then the quarterback who led them out of the doldrums may be able to scoop the Comeback Player of the Year award a la Phil Rivers in 2013.