ANAHEIM -- To make room for Thursday's starter, Matt Palmer, the Angels placed Darren Oliver on the 15-day disabled list with a strained left triceps and Kelvim Escobar was transferred from the 15- to the 60-day DL.
Palmer, who was recalled from Triple-A Salt Lake, will start in place of Oliver because the left-hander has been suffering from stiffness in his left shoulder since throwing four innings against the Mariners on Saturday.
"We did it to let his arm calm down a little bit," Angels manager Mike Scioscia said of Oliver, who had a 2.35 ERA over 7 2/3 innings and becomes the team's sixth pitcher to be placed on the disabled list this year.
The club opened a spot on the 40-man roster by transferring Escobar to the 60-day DL retroactive to April 3.
Escobar suffered a setback in his return from right shoulder surgery and said he won't be ready to come back until June instead of May, as was thought to be the case.
"If I come back as a starter, it's going to take a while," said Escobar, who is only playing catch at this point. "I have to build up to 100 pitches, so that will take four or five games, which is at least a month. And that takes us to June."
Rhett Bollinger is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.