Orioles left-hander Wei-Yin Chen has been placed on the 15-day disabled list with a right oblique strain.
Chen left Sunday's start against Minnesota with a pain in his right side. The move, made Tuesday, is retroactive to May 13.
Chen isn't sure how much time he will miss. Through an interpreter, he said, ''The only thing I can do right now is help myself and get better and not do anything to get worse.''
Signed as a free agent in January 2012 after starring in Japan, the native of Taiwan made 32 starts for Baltimore last year and is 3-3 over eight starts this season.
Also Tuesday, the Orioles recalled right-handed reliever Alex Burnett and infielder Yamaico Navarro. Burnett appeared in one game with Baltimore earlier this month.