Whether it's due to genetics, how they play the game, or not being in peak physical condition, some players seem predisposed to landing on the disabled list at some point during each and every season.
For some teams, their injury prone player is someone in a secondary role, such as a fourth outfielder or a nondescript setup man.
But for others, it's a big-time force in their lineup or pitching staff—someone who's absence has an adverse affect on the team's chances to succeed.
Some of these players have already dealt with the dreaded injury bug already in 2012 while others have been able to avoid any problems thus far.
Let's take a look at which players teams will be monitoring closely to make sure that the first bruise or strain doesn't manifest itself into something far worse.
Catchers get banged up on a daily basis and play at less than 100 percent all the time.
But Miguel Montero, who missed significant time in 2010 with a torn meniscus in his right knee, is essentially irreplaceable for the Diamondbacks.
With 40-year-old Henry Blanco as the primary backup and 27-year-old Konrad Schmidt, who appeared in four games for Arizona in 2010, as the only other catchers on the 40-man roster, the Diamondbacks would be in serious trouble should Montero miss significant time.
While there would be a drop-off in the game calling and defensive ability behind the plate, Montero's absence would create a gigantic void in the middle of Arizona's lineup.
Not only is Jason Heyward an important piece of the Braves in 2012, but he is the building block that they hope to mold their offense around for the next decade.
In order for that to be the case, Heyward needs to put 2011 where it belongs—in the past.
A shoulder injury that he suffered in spring training last year landed him on the disabled list and seemed to gnaw at him throughout the season. He finished with awful numbers: .227/.319/.389 with 12 home runs and 43 RBIs.
As Braves manager Fredi Gonzalez said: "Just a normal Jason Heyward year would be like going out and getting a top free agent."
Heyward suffered through an injury-plagued 2011, one that began in spring training with a shoulder injury that stayed with him throughout the season.
Staying healthy in 2012 will do two things for the Braves and Heyward—give him a full season in which to succeed and build up his confidence, and shake the "injury-prone" label that he currently has.
Last year's 129 games played were the most that J.J. Hardy has played since 2008, when he saw action in 146 games for the Milwaukee Brewers.
He's missed chunks of every season with a myriad of injuries, including a strained oblique that forced him to miss more than a month of action in 2010 for the Minnesota Twins.
The Orioles have a big-time shortstop prospect in waiting at Double-A in Manny Machado, but the earliest they would call him up would be late June, when they can ensure that he'll be under team control through 2018 and will not qualify as a "super two" player.
Hardy, who is off to a rough start for the Orioles in 2012 (.180/.261/.328), provides leadership and an excellent glove at shortstop, two things the Orioles would be hard-pressed to replace should he miss any significant time.
Sure, Josh Beckett isn't exactly endearing himself to Red Sox fans this season, with an ERA over four, but neither is anyone else in the Red Sox rotation.
Beckett, 31, has battled injuries throughout his career, throwing at least 200 innings in a season only three times in 12 years.
Whether he likes it or not, Beckett needs to step up and be the veteran leader on the staff this season. With no viable alternatives in the minor leagues to insert in his place should he miss any time, the Red Sox would be in worse shape were he be unable to take the ball every fifth day.
Kerry Wood is the pick for the Cubs because, realistically, he's the only injury prone player on the team—and he's already on the disabled list.
You could make a case for David DeJesus, but he's platooning with Reed Johnson, so it's not where he's an everyday player.
Neither is Wood, though the Cubs certainly expected more out of the 34-year-old than an 11.57 ERA, 2.57 WHIP and only 2.1 innings of work before having to be shut down with shoulder fatigue.
For the first time as a member of the White Sox, 30-year-old Jake Peavy is finally showing flashes of his former self this season.
Peavy, the 2007 National League Cy Young Award winner, sits with a 3-0 record, 1.88 ERA, 0.73 WHIP and 26 strikeouts over 28.2 innings pitched, including a complete game shutout of the Oakland A's last night.
Currently tied with Detroit for the lead in the AL Central, the White Sox simply cannot afford to lose Peavy for any length of time and are hoping that his injury woes are finally behind him.
Scott Rolen hasn't played in more than 133 games in a given season since 2006, yet he still remains a productive player at the age of 37.
While he's gotten off to a slow start for the Cincinnati Reds in 2012 (.175/.230/.246) with no home runs and only five RBI to go along with two errors in the field already, Rolen brings veteran leadership and provides some protection for Jay Bruce in the lineup.
The Reds can play Miguel Cairo and Todd Frazier at the hot corner in Rolen's absence, but neither provides nearly as much in the way of power with the bat.
A perennial 20/20 candidate when healthy, Shin-Soo Choo is seemingly always battling some sort of injury.
Limited by nagging injuries early in his career, Choo seemed to break the pattern in 2009, appearing in 156 games. Then 2010 came, and his total dropped to 144.
Then last season, Choo broke his thumb, landing on the disabled list, only to return and strain an oblique muscle.
This year, he's already injured his left thumb when he was hit by a pitch and spent a few days playing with a plastic thumb protector.
Choo, 29, is the Indians most complete position player and hits in the heart of the lineup.
They cannot afford for him to miss significant time, as they don't have anyone else on the roster or waiting in the minors who can replicate his production.
Tulowitzki's injuries are more the result of how hard he plays the game than anything else, but he's only been healthy enough to play in more than 150 games once since 2008.
A perennial All-Star, Tulowitzki has been on the disabled list a number of times throughout his career for a myriad of injuries, from a broken wrist to a pulled quadricep and a pulled oblique muscle.
Two weeks ago, he suffered a hip flexor injury in a game against the Houston Astros, an injury he's been able to play through thus far but something that the Rockies will need to monitor closely.
In two of the past three seasons, Delmon Young has dealt with injuries that have kept him out of action.
With the Minnesota Twins in 2009, Young was limited to only 108 games played, dealing with a myriad of injuries.
Last season, in Game 5 of the American League Division Series between the New York Yankees and Detroit Tigers, Young was forced from the game in the seventh inning after injuring an oblique muscle.
The injury was severe enough that Young would be left off of the Tigers roster for the American League Championship Series, only to be forced back into action after Magglio Ordonez's ankle injury made it a necessity to play Young, who was far from 100 percent.
The Tigers have a deep enough team where they would be able to absorb the hit if Young was forced out of action for any length of time. But Young is off to a solid start in 2012 (.267/.318/.367 with a home run and five RBI), and whoever replaced him—likely Don Kelly—wouldn't provide the same level of protection for Prince Fielder that Young does.
The man tasked with guiding the rebuilding Houston Astros pitching staff for the foreseeable future, 25-year-old Jason Castro has had two surgeries in the past year.
He tore his ACL in the second exhibition game in 2011 and was operated on in early March. After spending most of the year rehabbing his knee in order to return fully healthy at the start of spring training in 2012, Castro suffered another setback.
Playing in the Arizona Fall League, Castro injured his foot, resulting in December surgery to remove the seisamoid bone in his left foot, surgery that kept him out of action until spring training this year was already underway.
With 31-year-old journeyman Chris Snyder the only other catcher on the roster, an injury to Castro would be a devastating blow to a team that is slowly trying to return to respectability.
It took awhile, but in 2011 Alex Gordon finally lived up to some of the lofty expectations that the Royals had when they made him the second overall pick in the 2005 draft.
Poor performance was only one of Gordon's problems prior to last season.
Over the course of the 2009 and 2010 seasons, Gordon only appeared in a total of 155 games: 123 with the Royals, 32 in the minors due to a myriad of injuries, including hip surgery in 2010.
Off to a slow start in 2012, hitting .167/.276/.288 with two home runs and five RBI, Gordon is entrenched as the everyday lead-off hitter and left fielder for the Royals.
Keeping him healthy for a second consecutive season will help him to shed his "injury prone" label.
If it seems that Howie Kendrick misses significant chunks of the season each and every year, you'd be mostly right.
Kendrick, who made his debut with the Angels in 2006, couldn't stay healthy enough to play in more than 100 games until 2009, when he appeared in 105.
A multitude of injuries have affected him, primarily his hamstrings—which cost him some playing time last season as well.
Keeping Kendrick (along with Erick Aybar and Kendrys Morales, for that matter) healthy is paramount to the Angels reaching the lofty goals that they have for their team in 2012.
In 2010, it was a broken finger along with knee and ankle injuries.
In 2011, it was a knee injury that forced the Dodgers to shut him down at the beginning of September.
Needless to say, Andre Ethier has a penchant for getting injured, and that's not a road that either he or the Los Angeles Dodgers wish to travel down again in 2012.
With Ethier in the cleanup spot, behind Matt Kemp, the 30-year-old has played very well, and his 22 RBI are tied with Kemp for the National League lead.
A healthy, productive Ethier is key to the Dodgers potentially taking home the pennant in what appears to be a wide open National League West in 2012, especially with no viable alternatives on the roster or waiting for a promotion from Triple-A.
An entire slideshow could be produced cataloging the injuries that Jose Reyes has suffered since debuting with the New York Mets in 2003.
With the exception of a four-year period from 2005 through 2009 where Reyes played in no less than 153 games, the 28-year-old has averaged 83 games a season.
Now a member of the Miami Marlins after signing a six-year, $106 million contract this past off season, Reyes has managed to stay healthy thus far.
While he's been mediocre for the Marlins thus far, both at the plate (.215/.278/.354) and in the field, committing five errors in 15 games, Reyes is the table-setter at the top of Miami's lineup and a key piece to their aspirations of wearing the National League East crown in 2012.
Rickie Weeks has only managed to stay healthy once in his eight-year major league career (I'm omitting the seven games he played in 2003 from my count)—in 2010, when he appeared in 160 games for the Milwaukee Brewers.
Other than 2010, Weeks has only managed to play in over 100 games three times, and never more than 129 in any given season.
Whether it be an injury to his ankle, hand, knee or wrist, Weeks has the uncanny ability to not only get injured, but to miss significant time with his injuries.
There isn't really a viable replacement waiting to take his spot should he go down with another injury in 2012—prospect Eric Farris isn't playing all that well in Triple-A and the veterans that they have in minors, including Erick Almonte and Brooks Conrad, are part-time major league players at best.
When we list the injuries that Joe Mauer has had since 2004, it's nothing short of a miracle that he's able to move around as well as he does, much less continue to catch and play baseball.
In 2004, he had surgery to repair a torn meniscus in his left knee.
In 2007, he had a stress fracture in his left fibula.
In 2008, he had surgery to remove an obstruction from his kidney.
In 2009, he dealt with swelling in his back.
In 2010, he fought with a bruised left heel, tissue inflammation in his left knee (which required off-season arthroscopic surgery) and tendinitis in his right shoulder.
Last season, Mauer was knocked out of action due to a virus that caused weakness in both legs and soreness in his elbows, hips and shoulders. If that wasn't enough, he also battled pneumonia and continued to try and rehab his surgically repaired knee.
While Justin Morneau has been dealing with concussion-related issues for two years and a case could be made for him as the selection here, Joe Mauer is the straw that stirs the drink in Minnesota.
Some will argue that David Wright isn't injury prone, but I beg to differ.
In 2009, Wright missed nearly a month of the season with concussion symptoms after taking a fastball to the head.
In 2011, he dealt with a stress fracture in his back that forced him to miss two months of the season.
This year, Wright dealt with a torn abdominal muscle in spring training and then broke his pinky finger only a few games into the regular season.
Regardless, the 29-year-old is off to an excellent start this year, hitting .365/.452/.500 with two home runs and eight RBIs.
There's no understating how important a healthy David Wright is to the Mets and the psyche of both their fans and their players.
Since opting out of his contract during the 2007 World Series, Alex Rodriguez has missed an average of 38 games per season.
Surgery to remove a cyst on his hip in 2009 resulted in the discovery and subsequent surgery to repair a torn labrum. 2010 found him out of action for the majority of August and the beginning of September.
Last season, he had surgery to repair a torn meniscus in his knee, and he traveled to Germany this winter to undergo a controversial blood platelet therapy that was recommended to him by Kobe Bryant.
The Yankees options to replace Rodriguez when he's injured are either Eric Chavez, who is perhaps more injury prone than anyone else in baseball, and Eduardo Nunez, who turns fielding ground balls into an adventure every time one comes his way.
Over the past four seasons, Daric Barton has averaged 105 games played, leaving the Oakland A's with a hole at first base and still searching for a permanent option at the position.
In 2008, Barton missed time due to a neck injury suffered when he dove into an shallow swimming pool.
While falling into the Cleveland Indians dugout during a game in 2010, Barton fractured a finger, forcing him to the disabled list.
Last year, Barton had a torn labrum in his right shoulder, and injury that limited him to only 67 games.
An excellent defensive player and a patient hitter at the plate, Barton remaining healthy would provide some stability in a young A's lineup.
Only able to play in 115 and 103 games over the past two seasons, respectively, 33-year-old Chase Utley can now be called injury prone.
His knees, which hampered him throughout all of 2011 and have kept him out of action so far in 2012, are going to continue to be a constant source of concern for the rest of his career.
While Freddy Galvis has played excellent defense in the field, his bat is lacking (though his five extra base hits were tied for the team lead entering tonight's games). A .214/.241/.339 batting line simply isn't going to cut it for any team, much less a perennial World Series contender such as the Phillies.
Utley continues to work his way back to the Phillies, and reports today are pointing at him starting a rehab assignment in the minors sooner rather than later.
Last year, Jose Tabata missed seven weeks with a strained left quadricep and also dealt with injuries to his back and wrist as well.
The Pirates would love to see the 23-year-old Tabata stay healthy and play a full season so that they can see their young, talented outfield of Tabata in right, Andrew McCutchen in center and Alex Presley in left play a full season together and bring some stability to a team in a constant state of rebuilding.
Acquired by the Padres this winter from the Chicago White Sox to be the power bat that the lineup has lacked since Adrian Gonzalez left for Boston, Carlos Quentin has yet to play in a regular season game for San Diego.
Sidelined by knee surgery, Quentin recently took batting practice and ran in the outfield, working his way towards a return in the next few weeks.
Knee surgery isn't Quentin's only issue. The 29-year-old has never played in more than 131 games in any of his six year career, and he has a chronic plantar fasciitis issue that can flare up at any time.
The Padres knew that trading for Quentin was a risky move, but they certainly didn't plan on the risks to become a reality before he even stepped on the field at Petco Park.
There's no question that Brian Wilson was the most important injury prone player on the San Francisco Giants, and his penchant for injury reared its ugly head as he's undergone Tommy John surgery and won't pitch again until 2013.
The Giants have depth in their bullpen, with Santiago Casilla (the current closer), Javier Lopez and Sergio Romo all capable relief pitchers who could possibly handle the job.
Wilson was more than the closer for the Giants though. He was a team leader and someone who could attract the attention of the media, sometimes lessening the attention on some of his struggling teammates.
Going forward, the question isn't can the Giants recover from his loss, it's whether Wilson can recover from the second Tommy John surgery of his career.
When a player misses significant time one year, you can chalk it up to bad luck. When it's two years in a row, you can chalk it up to being injury prone.
Franklin Gutierrez, 29, didn't make his 2011 debut for the Mariners until May 18th, suffering from irritable bowel syndrome, something that continued to bother him throughout the season. Then in September, he suffered a severe oblique strain, one that ended his season.
After showing up to spring training in the best shape of his life and with his health under control, Guttierez suffered a partially torn pectoral muscle before even playing any exhibition games. Still on the disabled list, he only recently took batting practice and began throwing some soft toss.
Expected to be out of action until at least the middle of May, the Mariners have used Michael Saunders as his primary replacement.
Saunders has been underwhelming at best, showing the importance of a healthy Gutierrez patrolling the outfield at Safeco Field.
Carlos Beltran has battled knee injuries for the past three seasons, knees that limited him to only 145 games from 2009 through 2010.
Beltran, 35, has been hitting second for new Cardinals manager Mike Matheny, where he's hitting .279/.380/.525 with five home runs, nine RBI and three stolen bases.
With Lance Berkman on the disabled list and Matt Holliday off to a slow start, Beltran has been a big part of the Cardinals excellent play thus far in 2012 and figures to become even more important a piece as the season progresses.
It might be a stretch to call Luke Scott injury prone, but it's not a stretch to say that he's been an important part of Tampa's success to this point in 2012.
In 2010, Scott strained a hamstring late in May, requiring a stint on the disabled list. Then in July, he strained his hamstring while trotting around the bases after hitting a home run, resulting in more missed games.
Then last year, after trying to play through a torn labrum in his shoulder, Scott had shoulder surgery in July and missed the rest of the season.
As the Rays designated hitter and fifth hitter this season, Scott is hitting .295/.326/.659 with four home runs and 15 RBI while giving cleanup hitter Evan Longoria a surprising amount of protection in the lineup.
Since 2007, Josh Hamilton has been on the disabled list at least five times for a number of different injuries, and he played with a sports hernia among other maladies in 2011.
None of this, of course, includes his off-field issues, which you can choose to include in his injury history or not, depending on how you want to look at things.
Regardless, the fact remains that when he's healthy, Josh Hamilton is one of the best players in all of baseball and an integral part of the Texas Rangers success.
For the season, Hamilton is hitting .400/.420/.760 with eight home runs and 19 RBI from the third spot in the Rangers powerful lineup.
When he's banged up and unable to play, not only do the Rangers chances of winning get reduced but his teammates suffer as well—there are few players in the game capable of putting up the numbers and getting inside a pitcher's head like Hamilton can.
When the Toronto Blue Jays acquired Brandon Morrow from the Seattle Mariners in exchange for Johermyn Chavez and Brandon League in December of 2009, they knew that Morrow was a somewhat risky proposition.
Morrow, who was 25 at the time, already had issues with his biceps, elbow and shoulder on his pitching arm prior to joining the Blue Jays.
He started the 2011 season on the disabled list as he dealt with a right forearm strain and wouldn't make his season debut until nearly a month of the regular season had already passed.
When healthy, Morrow is the Jays number two starter behind Ricky Romero. While they have a number of pitching prospects in the minor leagues, none of them are quite ready for the big show, making Morrow's health even more important than usual.
Since 2006, Ryan Zimmerman has missed an average of 24 games a season due to injury, yet the Nationals decided to throw caution to the wind and signed him to a six-year, $100 million extension this past winter.
He missed two months of the 2011 season dealing with an abdominal strain, and as of today he is headed for an MRI on his inflamed right shoulder, an injury that's kept him out of the lineup since Saturday.
When healthy, Zimmerman is one of the preeminent third baseman in the league, but his penchant for getting injured certainly is cause for concern going forward and could throw a monkey wrench into the Nationals plans to compete in a wide-open National League East this season.