The New York Yankees placed relief pitcher Joba Chamberlain on the disabled list yesterday because of a strained flexor muscle. The right hander could miss a month due to the injury.

Yankees manager Joe Girardi said Chamberlain will be shut down for 10 to 14 days and then resume throwing, but he warned that such injuries can be a sign of something worse or could take a month or more to heal. Chamberlain had an MRI yesterday that revealed the injury, and he will undergo a second MRI today that will utilize an IV of dye to reveal more details of the elbow's condition.

New York was settling into a routine of using Chamberlain as the eighth-inning reliever, acting as a bridge between the starting pitcher (or middle relievers) and closer Mariano Rivera. Chamberlain earned 13 holds this season in 28 2/3 innings. Setup man Rafael Soriano went on the DL on May 14 due to an inflamed elbow ligament.

Girardi said he will look to David Robertson to be the late relief pitcher, with Luis Ayala and Boone Logan to pick up Robertson's middle innings. Robertson holds a 1.46 WHIP (walks plus hits per innings pitched) and a 1.16 ERA in 23 1/3 innings this season.

Chamberlain said he feels good enough to throw right now, but he became concerned that something serious might be wrong with his arm. There's no pain. You can do whatever you want but as soon as I'm done throwing it just gets tight. It's one of those things that you have to take care of so it doesn't cause compensation to hurt something else, the 25-year-old pitcher said.

This is Chamberlain's second stay on the disabled list in his 3 1/2 years in the major leagues. On Aug. 4, 2008, the pitcher went on the 15-day disabled list with rotator cuff tendinitis.