"Right now, for this series against the Orioles, Palmer will pitch out of the bullpen, but he has the chance to make it back in the starting rotation," said manager Mike Scioscia.
O'Sullivan will pitch Saturday against the Orioles, his fourth start of the season. In three starts this year, O'Sullivan is 2-0 with a 3.00 ERA.
Palmer is 7-1 with a 5.00 ERA, however he has struggled of late, giving up six earned runs each in his past two starts against the Rockies and D-backs.
Palmer pitched out of the 'pen on Wednesday against the Rangers, throwing two innings and giving up no earned runs.
Throughout the season Palmer has said he would do anything to help his team win, so for the righty, that will mean coming out of the bullpen for the time being.
Knowing how stretched out and banged up the Angels bullpen has been recently, Scioscia felt Palmer was the right person to move to the bullpen.
"Where O'Sullivan is, we didn't want to put him in the 'pen," Scioscia said. "Palmer is more suited for this role right now."
Quinn Roberts is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.