MLB Rumors: Available Pitchers Who May Have a Late-Season Impact

The MLB season has only hit the one-quarter mark, and several teams are already searching for help in their starting rotation due to either injuries or underwhelming performances.

Luckily, there are currently a number of free-agents pitchers that can potentially have an impact down the stretch.

Here are five available pitchers who fit that description.

Jason Marquis, 33

The 33-year-old right-hander defines an average pitcher. He's had an ERA+ of over 100 only six out of 13 big league seasons, with the highest in 2001.

Marquis, however, is an intriguing option for teams because of his years of postseason experience. He pitched in the playoffs for Atlanta, St. Louis, Chicago and Colorado every season from 2000 through 2009. 

The past two seasons have been a struggle for the Staten Island native, who pitched to a 9.53 ERA last season and a 8.47 this season prior to being designated for assignment by Minnesota.

According to Andy Martino of the New York Daily News, the New York Mets have expressed interest in signing Marquis in the past, and believe he would be interested in pitching for his home state if the Mets were in need of a starter.

The Mets are looking to find a competent replacement for Mike Pelfrey. Marquis could potentially be a pitcher who brings a veteran presence and provides the Mets with some rotational depth for the short-term.

Roy Oswalt, 34

Roy Oswalt is an intriguing option due to his incredible track record, which features one of the highest career winning percentages in major league history.

The diminutive right-hander has extensive postseason experience, and is a three-time All-Star. His last postseason game was in last year's NLDS while pitching for the Philadelphia Phillies.

The Texas Rangers, looking to replace injured Neftali Feliz, could potentially be in the running for Oswalt.

General Manager Jon Daniels has not directly stated the team's interest, reports Master Tesfatsion of ESPN Dallas/Fort Worth, but acknowledged that the team values him as a potential candidate for the rotation.

He has never pitched in the American League, which could be a red flag. However, he has been extremely consistent in his career and could still remain an effective pitcher as long as his health and stamina are at full strength. 

John Lannan, 27

Lannon is only 27-years-old, and is costing the Washington Nationals $5 million to pitch in Triple-A.

Lannon was demoted to the minor leagues due to the Nationals' incredible rotation depth. The No.5 spot in the rotation went to Ross Detwiler, much to the chagrin of Lannon.

Last season he went 10-13 with a 3.70 ERA for the Nationals, who would have a much easier time trading him if it wasn't for his salary. 

Gordon Wittenmyer of The Chicago Sun-Times notes the Chicago Cubs have expressed interest in the left-hander, who has never pitched outside of the National League.

GM Mike Rizzo could help the Nationals' chances of making the postseason if he uses Lannon as trade bait to land a power bat to his lineup. 

Brandon Webb, 32

It was only half a decade ago that Brandon Webb was one of the most dominating pitchers in the National League.

He won the Cy Young award in 2006 for the Arizona Diamondbacks, and placed second for the award in both 2007 and 2008.

Webb has suffered through a rash of injuries, which has limited his value despite his impressive track record.

He signed a one-year deal with the Texas Rangers last season, but did not pitch in the big leagues after undergoing another rotator cuff surgery. 

GM Jon Daniels stated, via Richard Durrett of ESPN Dallas-Fort Worth, that Webb could be a late-season option once he regains his command and velocity, which has yet to reach Major League standards. 

Brandon League, 29

The Seattle Mariners are not going to win the AL West this season because of their lack of impact players.

They could help their offense by trading closer Brandon League for an experienced batter. This would not be a move not just for 2012, but for the future. 

Scouts in the American League have recognized League's value, especially during a season where closers have been incredibly ineffective. The Mariners have a serious "trade chip", according to former Nationals GM Jim Bowden in an interview on ESPN 710 Seattle, and many expect League to be dealt before the deadline.