OAKLAND -- A's left-hander Scott Kazmir exited Wednesday's start against the Tigers after just three innings due to left shoulder tightness.

Kazmir walked three but also struck out four and did not allow a hit before his sudden departure. He was replaced by right-hander Dan Otero to begin the fourth inning and remained in the dugout throughout the inning before leaving for the clubhouse.

O'Flaherty to begin Minor League rehab assignment

OAKLAND -- A's reliever Eric O'Flaherty, who has been sidelined by a strained left shoulder since the beginning of the month, was scheduled to begin a rehab assignment with Triple-A Nashville on Wednesday evening.