10 MLB Players on Contending Teams Most Likely To Break Down

As we hit mid-August, it's time to consider which players from contending teams are most susceptible to breaking down, whether in terms of injury or performance.

Some of those on the following list are likely to break down because of the natural limitations that come with age and some because of the pressures of having the expectations of an entire fan base placed squarely on their shoulders.

Here are the 10 most likely players from pennant-chasing clubs to break down as the latter part of the season plays out ...

Yovani Gallardo, Brewers

The Milwaukee Brewers are one of the hottest clubs in the game, and one of their best arms belongs to starting pitcher Yovani Gallardo.

But as talented as Gallardo is, he seems to have trouble in the month of September.

Since 2008, Gallardo has a 4.21 ERA during the month of September. His lifetime numbers post-All-Star break include an ERA of 5.10.

From 2008-2010, opponents are hitting .266 off of Gallardo in the second half, whereas they hit just .218 in the first half.

Derek Jeter, Yankees

Despite the extreme criticism Derek Jeter received after a below-average 2010 (.270, 10 HR, 67 RBI), the Yankee Captain has rebounded to post much better numbers thus far in 2011, hitting .291 through 98 games.

But at age 37, Jeter is clearly on the decline, far from the numbers that have made him a .313 career hitter with a lifetime .383 on-base percentage.

Between the inevitable limitations that come with age and the pressures of justifying a superstar-caliber salary with New York, Jeter may have a rough September and postseason in 2011.

Ryan Howard, Phillies

As the leading run producer for the team with the best overall record in baseball, Ryan Howard has a lot riding on his shoulders going into October, where the Phillies have visions of a world championship in 2011.

Howard, however, has struggled against an ever-improving National League arsenal of pitching.

In the 2010 postseason, Howard had no home runs, no RBI and 17 strikeouts in 33 at-bats (that's roughly a punch-out every two at-bats).

Carlos Beltran, Giants

The defending world champs landed the biggest pre-trade deadline bat on the market in Carlos Beltran, and so far, things haven't worked out so well.

Beltran hit just .244 in his first two weeks as a Giant, and then, a hand injury forced him to go on the disabled list.

The Giants are hoping Beltran will return to the form that produced for the New York Mets prior to his move to San Francisco, but with an offense that is struggling so badly, the pressures to produce could very well be too great for Beltran, who has never played on a club with an offense so anemic.

Jason Heyward, Braves

Jason Heyward was as highly-touted a prospect as they come in 2010, but his postseason debut with the Braves was far short of stellar.

After a rookie regular season in which he hit .277 with 18 home runs and 72 RBI, Heyward struggled mightily in the postseason, hitting just .125 in the NLDS.

Since then, he's had trouble finding his stroke and is hitting just .220 with 12 home runs and 31 RBI so far in 2011.

Adrian Gonzalez, Red Sox

Anyone who hasn't been to the postseason in five years and is coming off his first season with a large-market team that paid him over $150 million to be their first baseman, is going to have a lot of scrutiny with each October at-bat.

That's what life will be like for Adrian Gonzalez, who is having a fantastic season for his new club, the Boston Red Sox (.343, 18 HR, 92 RBI), but who will be expected to come up big in the postseason as well.

And since Gonzalez has only had 14 career postseason at-bats, without an extra-base hit or RBI, performing in the playoffs will be uncharted territory for Boston's newest big bat.

C.J. Wilson, Rangers

C.J. Wilson has become one of the best starting pitchers for the defending American League champion Texas Rangers, but he had a real rough go of it last September and then into the postseason.

In September 2010, Wilson had his worst month of the season, going 0-3 and a 6.26 ERA.

Then in the postseason, Wilson struggled as well, going 1-2 with a 3.70 ERA, his last outing coming against the eventual World Series winners, the Giants.

September has also been Wilson's worst month since 2008.

His ERA for that month is 4.66.

Justin Verlander, Tigers

The man who is primed to claim the American League Cy Young Award in 2011, after his sheer domination of AL hitters over the first five months of the season, could also be one to break down in September and October if the Tigers make it that far.

Justin Verlander (18-5, 2.31 ERA, 0.88 WHIP) has historically struggled during the month of September, with a 3.97 ERA for the month over the past three seasons and an opponents' batting average of .263.

Travis Hafner, Indians

Travis Hafner is a career .282 hitter, but from 2008 to 2010, the month of September wasn't kind to the Cleveland Indians' designated hitter, as Hafner hit just .238.

Ryan Roberts, Diamondbacks

Ryan Roberts has been an important component for the D'Backs and their surprising surge to the top of the NL West standings.

But if recent history is any indicator, Roberts might have a hard time come September and beyond if Arizona can manage to hold off the defending champion Giants, who currently trail the Snakes by 2.5 games.

Roberts is hitting just .223 in September over the last three seasons, with just a .279 on-base percentage.

By contrast, Roberts is hitting .259 with 16 homers and 50 RBI so far in 2011.