"It was as sore today as it has been," Orioles manager Buck Showalter said before Saturday's game against the Giants. "He was adamant about not going on the DL when he left, but he doesn't want to leave the bullpen short. I'm confident we can get this resolved."
The Orioles recalled right-hander Tyler Wilson from Triple-A Norfolk to take O'Day's place. Wilson is 4-6 with a 4.98 ERA in 17 games, including 13 starts, for the Orioles this year.
"We did that before when Darren was out," Showalter said. "The only way to gain experience is to do it. Some guys have to grow up quick."
Rick Eymer is a contributor to MLB.com and covered the Orioles on Saturday. This story was not subject to the approval of Major League Baseball or its clubs.