Every year, it seems there are MLB players who are usually consistently good but then for whatever reason end up having terrible years.
There are also those who are inconsistent, forget to work out over the offseason or have other issues that cause them to have a poor year.
This can even apply to legends of the game; sooner or later everyone starts to slow down due to age. Sometimes a team can sense it coming, but other times a sharp drop occurs out of nowhere, like Todd Helton and Carlos Lee had in 2010.
Here are 50 MLB players who look to be in trouble in 2012. This list is in no particular order, as I'm mixing and matching those who seem destined for a bad year and those who would be shockers.
John Lackey's already in trouble. On top of an albatross of a contract and two extremely disappointing seasons in Boston, Lackey opted for Tommy John surgery at the end of October.
It's possible he played with an injured elbow, thus decreasing his fastball velocity and his effectiveness, but only time will tell if he can salvage the last couple years of his contract after missing this season.
Alex Rodriguez is already the most scrutinized player by his own fans in MLB by a mile, and the fact that he was merely decent in 99 games did not help matters.
Now A-Rod is undergoing an experimental procedure on his knee in Germany. It could help revitalize his career and turn him back into a star, but it could also be the beginning of the end for him if it doesn't work out.
The past three seasons, Grady Sizemore has had two settings: injured or mediocre and trying to avoid injury.
The Sizemore of old has been missing in action, and unless the fact that he's on his last chance sinks in, 2012 is going to be a pain to get through.
Over the past few seasons, those who have won the NL Rookie of the Year have had big-time sophomore slumps. The last one to continue his dominance was Ryan Braun in 2007.
Will Craig Kimbrel continue that trend?
His season as a whole says no, but his struggles in September say yes. Of course, Atlanta is hoping he remains dominant.
Speaking of Ryan Braun, the reigning NL MVP is usually a sure thing.
However, one of two things will happen.
Braun will either serve a 50-game suspension, missing a big chunk of the season, or he will get it appealed and will likely struggle after having to deal with that all offseason.
Pitchers brought to MLB through the posting system or from Japan in general have had mixed success; for every Hideo Nomo, there's been a Kei Igawa.
The Rangers will give a huge contract to Yu Darvish, so the pressure will be on.
The fact that Texas is trying to win now adds to the pressure, which could end up being too much. At the same time, Darvish could end up not signing at all, which would put the Rangers in a bad spot pitching-wise.
The Marlins paid big-time money for Reyes after a career year.
Unfortunately, when they purchased Reyes, they also bought his injury history.
The pressure will be on to play as many of the 162 games as he can as Reyes tries to live up to the contract.
Speaking of big contracts, Jayson Werth's first season as a National was a bust. He hit 20 home runs, but not much else.
If the Nationals want to contend in 2012, then the hitting crew needs to step up, and the Nats and Werth both know it starts with him.
He could be in big trouble even with a decent season since that's not what Washington paid for, and the front office may start to get impatient.
After a great rookie season that sabermetricians dismissed as lucky, Austin Jackson ended up proving them right, as he struggled big time in 2011.
Jackson can still hit triples and make plays when needed, but he'll need to keep his average over .250 so as not to hurt the Tigers, who are trying to win.
If anyone actually signs this guy in 2012, then they're bringing the trouble on themselves.
This is a "will" rather than a "could," though it's more realistic that Manny will be watching games on TV this year than from the field.
Since his great 2008 season, Daisuke Matsuzaka has either been injured or ineffective. He is now in the final year of his contract, and even worse, he is coming off Tommy John surgery.
Rehab for the injury is usually 12 to 14 months, so Dice-K is probably looking at a return at the All-Star break, potentially sooner. He's a free agent after next season, so the second half of the year will be crucial for his next contract.
Aside from the pressure of pitching for the Yankees, Joba Chamberlain's not exactly in the best of shape.
The two combined have caused him trouble in the past, and he is usually a sure thing as someone to watch since he could end up being in trouble. After Tommy John surgery derailed his season last year, he's likely looking at a mid-year comeback.
Bobby Jenks has always been fairly out of shape, but he was effective during his time with the White Sox, so it wasn't looked at too closely.
After a terrible 2011 season with Boston, however, he's in trouble since another poor season will likely end his major league career.
Jonathan Broxton is only 27, yet he is already falling apart due to tipping the scales at around 300 pounds. That led to a poor 2011 season that he missed most of.
A new start in Kansas City is precisely what he needed, but if he doesn't drop the weight, then he'll end up known as a flash-in-the-pan reliever.
The only surprise here is how long you probably had to wait to get to this slide.
The Cubs, other teams, the fans and maybe even Carlos Zambrano himself know he's in big trouble and that this year will pretty much determine whether he'll pitch eight more years or eight more months.
Carlos Lee had somewhat of a comeback season in 2011 after a bad 2010. His high WAR was thanks to better defense due to playing first base part of the season.
The big 35-year-old is likely to start slowing down more, especially since he is now in the final year of his contract and would likely be a year-to-year pickup now.
Aubrey Huff had a great 2010 season, helping the Giants win the World Series.
But every so often he has a great year and then falls back to having a few mediocre seasons.
Huff has an option in 2013, and the Giants are going to want one of those good years in 2012, especially since not many others in San Francisco can provide that kind of pop. He was noted as being out of shape this past season, so there could be hope for him.
The Giants second baseman has been somewhat productive when healthy since joining the Giants.
The problem, however, is that he hasn't been healthy.
Despite the fact that Sanchez in a contract year, it doesn't seem he's able to do the grind of a 162-game season anymore.
Jair Jurrjens will probably be fine in 2012, but because he's been so heavily put on the trading block, he could have issues next year after having to deal with everything, especially if he remains in Atlanta despite its best efforts.
Francisco Liriano has been very inconsistent in recent years, and the Twins need him to step up.
Besides, he's eligible for free agency in 2013, so the time to reappear would be now.
Still, all the turmoil in Minnesota this past year could take its toll on Liriano, as it seems to have done already.
For whatever reason, the Nationals just don't seem to have a great track record of keeping pitchers healthy, and their acquisitions don't always work out. More to the point, it seems quite frequent that A's pitchers don't seem to last long elsewhere.
Gio Gonzalez will be one of the key pitchers on the team, so he has to hope that history does not repeat itself.
Adam Dunn had a historically bad season in 2011.
As a result, he doesn't just need a comeback year but needs to quickly revert to the Adam Dunn of old, or else there will be questions in Chicago.
I noted earlier that A's pitchers seem to struggle when pitching on other teams, and that goes double for anyone on the San Diego Padres.
Heath Bell played great as a closer, but can he continue that success on a new team? History says no.
Milton Bradley will absolutely be trouble in the clubhouse if a team actually decides to sign him.
The odds of that happening are thankfully slim, as it seems all 30 teams are tired of him.
Prince Fielder could be a troublesome situation. He looks like he will sign relatively late in the offseason thanks to Scott Boras, and as a result he may not be in the best shape.
Combine that with moving pains, and Fielder will likely struggle in his first year with a new team, though he should rebound.
As good as Andruw Jones may have been in his prime, teams remember his tenure with the Dodgers better, where he showed up out of shape and was horrible on the field.
The free agent is getting up there in age and could very well have problems again, especially if he's a late signee.
Vicente Padilla missed most of the 2011 season due to injury and just seems to be getting more banged up as the years go by.
As a result, a team signing him may get more trouble than it's worth.
Padilla can be a good pitcher when healthy, but I don't see that happening again.
While Fausto Carmona would be an easy addition on this list, he's an afterthought at this point.
Ubaldo Jimenez, on the other hand, was the player the Cleveland Indians gave away the farm for.
Due to his struggles in 2011, there's a lot of concern about Jimenez heading into 2012, and the pressure will certainly be on.
Having Scott Boras as one's agent can be a curse, and every so often a player signs so late that he ends up struggling after that.
Ryan Madson looks to fill that role this year since Boras is currently occupied with Fielder, and every day the closer openings are filling up.
It seems like Hanley Ramirez will stay in Miami for 2012, and if that's the case, it's going to be a rough year.
He will have to learn third base, and we will likely see a lot of frustration to go along with that this season from both sides.
Wright has been one of the best third basemen in the game year after year despite his struggles in 2011.
However, he at least had others in the lineup to help him out, such as Jose Reyes.
In 2012, Wright won't have much around him, and that could cause his production to suffer since teams know they will be able to work around him.
Mike Pelfrey seems to bounce back and forth, having a solid season and then a terrible one.
As a result, in 2012 he should have a decent season.
Instead, he seems to be wearing thin with Mets fans, and the backlash could have an impact on how Pelfrey pitches this season.
With the early releases of Luis Castillo and Oliver Perez, the Mets are fine cutting ties with players when they don't perform.
Jason Bay may have a few years left on his contract, but he could be next.
Bay hasn't done much of anything since joining the Mets, and if he can't get it going this year, he's next on the chopping block.
Johan Santana was a sure thing when he originally signed with the Mets, but he missed the 2011 season due to shoulder surgery.
Recovering from shoulder surgery is always a huge red flag with pitchers, so the Mets are going to be keeping an extra eye on Santana to make sure he does all right.
Joe Nathan was one of baseball's elite closers before Tommy John surgery cost him the 2010 season. He recovered and played in 2011 but was not the same pitcher.
Combine that with the fact that he's going to be playing in a hitter's park next year, and Nathan could struggle big time.
The Los Angeles Angels of Anaheim made a stupid decision acquiring Vernon Wells in 2011, since the Blue Jays had him on their trouble list to begin with because he wasn't playing to his potential.
Wells' stats in 2011 proved what Toronto thought, and that will likely continue in 2012.
Todd Helton has been so great for so long for the Rockies, but 2011 was likely his lone comeback year, and 2010 is more consistent with how he'll perform.
The Rockies are building for the future, and the 37-year-old first baseman is not going to be part of that.
Instead, it looks like he will just play out his contract and probably play to the smaller numbers.
After a good offensive season in 2010, Kelly Johnson regressed and was a serviceable second baseman at best.
As a result, the Diamondbacks and Blue Jays traded struggling second basemen.
While a change of scenery will definitely be good for Aaron Hill, I'm not sure if Johnson will rebound. It feels like 2010 was the fluke, and it may be tough for Johnson to prove others wrong.
Jose Mijares has been a solid reliever for the Twins the past few seasons, but that's no thanks to the shape he's in. Mijares was out of shape this past season and as a result was non-tendered.
The Kansas City Royals are giving him a shot, and he'll have to watch his weight to make the most of that opportunity.
After having promising seasons in 2009 and 2010, Hughes reportedly came to spring training overweight and struggled in 2011, spending time on the disabled list for arm fatigue.
If Hughes is out of shape for spring training this year, that's going to be a major problem for the Yankees and their rotation. CC Sabathia can work around his weight, but few other pitchers can.
Justin Morneau hasn't quite been the same since his near-MVP win in 2008. He had a nice 2009 season, but his 2010 and 2011 seasons were injury-riddled.
Morneau's injuries seemed to have long-term effects, since his numbers on the field last year were quite bad, and unless he's fully recovered mentally and physically, it's going to be a long year for him.
Lance Berkman, known in some circles as Fat Elvis, is one of those hitters who tends to alternate great and bad seasons. He had a great year for the Cardinals this past season but struggled with the Astros and Yankees the year before.
As a result, Berkman is due for a mediocre season, and the Cardinals are going to be watching him closely.
Bartolo Colon's weight has not been an issue before, and he's had several amazing seasons in his career.
However, he struggled down the stretch with the Yankees this past season, and he no longer has the conditioning to go a full year.
This would be a problem, especially if he's picked up by a contender, since Colon wouldn't be able to do much in the playoffs.
Last up on the list of out-of-shape pitchers is Tommy Hunter.
Hunter pitched well the first few seasons the Rangers had him, but he struggled with Baltimore.
If he wants to continue to be a good pitcher, he's got to improve his conditioning. Hunter can get away with an ERA around five in Baltimore, but it's still not recommended.
Melky Cabrera is a tough player to figure out. He can put up very good offensive numbers, like he did last year with Kansas City, but he's definitely inconsistent.
The fact that he's going to San Francisco is cause for concern, as his power could very well disappear there.
Ted Lilly seems to be a pitcher who's on his way down. He'll be 36 when the season starts, and while he had an OK year for the Dodgers in 2011, Dodgers fans seem to have already written him off, knowing that he will in fact struggle in 2012.
Scott Rolen had a nice comeback year in 2010 but only played 65 games in 2011. He's not a guy who can seemingly play every game anymore, and his diminishing skills could cause trouble for Cincinnati in 2012.
Tsuyoshi Nishioka was purchased by the Minnesota Twins to shore up their infield.
Instead, Nishioka played only 68 games and did not look good in those games.
I'd say it's first-year jitters, but usually imports from Japan start out great before slowing down, which is cause for concern in Minnesota.
There's no question that Ichiro is a Hall of Famer, but after somewhat struggling in 2011, it looks like his career is beginning its downward slope.
The Mariners are going to realize this in 2012 if they haven't already, and they'll have to start working around that since he's been one of the few reliable bats in Seattle.
I'm ending this list with Cabrera and the caveat that every year he seems worthy of noting that he could be a problem due to various issues—yet every year he has an MVP-type season.
Yes, he could be trouble since he's never entirely been in shape, but more realistically Cabrera will probably finish in the top five in MVP voting again.