The Orioles designated Chris Tillman for assignment after reinstating him from the 10-day disabled list on Friday.
Tillman's recovery from a back injury was slow, and he needed to make three rehab starts for Triple-A Norfolk. The right-hander said he sustained the injury while dodging a foul ball that dipped into the dugout against the Tigers on April 28.
Before being placed on the DL, Tillman struggled mightily, going 1-5 with a 10.46 ERA and a 2.21 WHIP this season. Batters were hitting .365 against him.