The Boston Red Sox have placed reliever Andrew Bailey on the 15-day disabled list because of strained right biceps.
Boston activated lefty reliever Craig Breslow from the DL on Monday.
The 28-year-old Bailey started the season as the setup man, but was elevated to the closer's role when Joel Hanrahan went on the DL in April with a strained right hamstring.
Bailey was 1-0 with a 1.46 earned-run average and five saves in 13 games before going on the DL.
Bailey missed most of last season after having surgery on his right thumb during spring training. The right-hander also missed a large portion of the 2011 and 2010 seasons when he was with Oakland because of injuries.
Breslow started the season on the DL with shoulder tendinitis.