We all have different definitions of the term "sleeper" so I should probably give mine before we get started. I don't have an arbitrary cutoff in ADP or rigid definition. What I'll be talking about below are 12 players I feel are being overlooked on Draft Day for a variety of reasons.

Some of these guys are young players that need an injury to be relevant, but I think people are underestimating the likelihood of that injury. Others are older players that battled injuries last season and saw their perceived value fall because of that. Finally, there are players that just flat out stunk in 2015, but should be better because of a change in circumstances or regression.

What all of these players have in common is their performance should outpace the consensus expectation. These are the 12 sleepers that will make you look smart in December, if not on draft day.

Matt Ryan
ATL • QB • 2
2015 stats
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You don't generally get to list a player that has a five year run as a top ten player at his position as a sleeper, but Ryan's 2016 was that bad. I'm not going to argue how much of Ryan's disappointing campaign was luck, so much as I'll argue that a bounceback is extremely likely. In 2016 Ryan matched his career averages for yards, completion percentage, and yards per attempt. He struggled mightily in the red zone and saw a massive drop in his touchdowns.

I've talked many times about how touchdowns can be fickle and Ryan's 2016 is no different. He was just the third quarterback of all time to throw for 4,500 yards and less than 25 touchdowns. The most recent comparable would be Matthew Stafford's 2012 season. Stafford threw for 29 touchdowns the next season.

If Ryan just does what he did last season and has a normal touchdown rate, he's going to be a top 12 quarterback. He's being drafted around QB20 and that's about where the other experts have him ranked. In two-QB leagues Ryan is going to be a flat out steal and I'd even consider him as a borderline QB1 late in standard leagues.

Andy Dalton
CHI • QB • 14
2015 stats
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Contrary to popular belief I am not contractually obligated to write nice things about Andy Dalton, but I'm going to anyway. After a disappointing 2014, Dalton was on his way to the best year of his career before missing the final 3-plus games of the season. If he hadn't gotten hurt I'd probably be talking about how touchdown regression was going to hurt him. Because he got hurt, he's being drafted behind guys like Blake Bortles and Derek Carr.

The loss of Hue Jackson and the injury to Tyler Eifert are certainly warning signs for Dalton, but we're talking about a guy that has twice shown the ability to perform like a top five quarterback. One of those seasons was before Jackson and Eifert were important parts of the offense. Dalton and Ryan will be my top two targets when I punt quarterback and wait until the later rounds of the draft. Pairing these two provides you with a ton of upside and the ability to play the matchups each week.

Arian Foster
MIA • RB • 29
2015 stats - played 4 games
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There is a chance that Arian Foster is done as a football player, but his upside is not accurately represented by his current ADP. Foster, who says he should be ready in a month, isn't being drafted until the 10th round after at least 36 running backs have been taken. That's fair if Foster accepts a backup job and never regains his form. At that stage of the draft I already have my starters and I'm betting on upside, Foster has it in spades. If he lands somewhere like Miami, with a chance to earn significant carries, his ADP is going to skyrocket. At the very least you should keep an eye out for reports on who is talking to Foster.

Charles Sims
TB • RB • 34
2015 stats
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I expect Sims to gain some steam in PPR drafts once we get closer to the season, but he's going to have value in standard leagues as well. I love Doug Martin this year and expect him to be a top ten back if he stays healthy, but he's only done that twice in four years. While Sims is a great pass-catcher that's far from the only thing he does well. Sims averaged 4.9 yards per carry in 2015 and has the size to get the job done at the goal line. With his pass-catching ability, Sims is being valued at his floor. If Martin goes down, Sims has a great chance of being an RB1.

Cameron Artis-Payne
CAR • RB • 34
2015 stats
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Where I think many of the running backs above could be sleepers without a major injury, Artis-Payne is counting on Jonathan Stewart getting hurt. Considering Stewart hasn't played 16 games since 2011 that seems like a fairly safe bet. Artis-Payne would have to battle for scraps with Mike Tolbert but Tolbert is getting up there in age, so I believe an extended Stewart absence would give the Panthers sophomore back a chance to thrive in one of the best running attacks in football.

Vincent Jackson
TB • WR • 83
2015 stats - played 10 games
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Jackson was a colossal disappointment even before his season-ending injury, but his stock has fallen too low. Even on his current pace last season Jackson would have ended the season with 868 yards and five touchdowns. Factoring in improvement from Jameis Winston and a fully healthy Jackson, I would anticipate his fifth 1,000 yard season in the last six.

In 2015 Jeremy Maclin finished as WR16 with 1,088 yards and eight touchdowns. Kamar Aiken was WR30 with 944 yards and five touchdowns. I would anticipate a healthy Jackson finishing somewhere in that range which makes him a huge value at his current ADP. Also, it's a contract year for Jackson if you're into that kind of thing.

Markus Wheaton
PHI • WR • 80
2015 stats
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Wheaton will likely be the second option behind Antonio Brown in the Steelers receiving corps. He played five games without Martavis Bryant in 2015 and the results were mixed. In those five games he totaled nine catches for 228 yards and a touchdown which over a full season projects out to about what he's done each of the past two years. The disappointment of last season has really lowered his perception heading into 2016, but the situation is even better, past disappointments aside. Wheaton has a good shot of turning volume into a top 36 season at the wide receiver position.

DeSean Jackson
LAR • WR • 10
2015 stats - played 10 games
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Much like Vincent Jackson, DeSean's spot on this list is mostly injury related. The Washington wide out played on ten games last season and was fairly ineffective when he did play. But if people are buying in to Kirk Cousins you have to see the upside with Jackson. Jordan Reed, when healthy, will draw attention to the middle of the field leaving the speedy wide receiver to single coverage on the outside. Jackson has feasted on single coverage throughout his career and his 17.6 yards per reception from 2015 illustrate that he still has the speed to take the top off the defense.

Antonio Gates
LAC • TE • 85
2015 stats - played 11 games
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Antonio Gates is 35 years old and only played 11 games in 2015. He was still a top 12 tight end. The Chargers gave him a new deal and I fully expect him to be overlooked heading into the 2016 season. Gates had been drafted outside of the top 12 tight ends each of the past two seasons and he's cruised past those expectations despite battling a variety of ailments. I wouldn't expect Gates to get through 2015 injury free but he'll give you borderline top 5 production when he's healthy and you can stream the weeks he misses.

Kenyan Drake, RB, Miami

Drake was only part time back at Alabama but his explosiveness is already being talked about in Miami. He currently sits third on the depth chart and is being discussed as a return man, but I believe he's the best back on the roster not named Jay Ajayi. Ajayi's knee is a ticking time bomb, that may not go off this season. If it doesn't, the second year back should be very productive. If it does, Drake could be thrust into a starting job as a rookie.

Kenneth Dixon, RB, Baltimore

I'm not even sure Dixon needs an injury to eventually be the man in Baltimore. Justin Forsett is on the wrong side of 30 and has just one productive season to his name. Javorius Allen was fairly underwhelming when pressed into action last season. Dixon has good receiving skills and all the tools to be a three-down back. If he gets off to a good start in camp his ADP should skyrocket.

Michael Thomas, WR, Saints

Thomas has already earned high praise at OTAs in New Orleans with his work ethic and ball skills. He has prototypical wide receiver size and a game that would fit extremely well with Drew Brees and Brandin Cooks. Thomas took some first team reps at OTAs and I wouldn't be surprised if we get similar reports once training camp starts. It should not surprise anyone if Thomas is the most productive rookie wide receiver in the league.