Jerome Williams placed on DL

ANAHEIM, Calif. -- The Los Angeles Angels placed pitcher Jerome Williams on the 15-day disabled list Wednesday, two days after he experienced shortness of breath and passed out in the team's clubhouse.

Williams, 30, spent Monday night in the hospital. He has been through a battery of tests since, but the right-hander said Wednesday that doctors haven't given him a specific diagnosis.

"I really couldn't breathe. It's probably like a mixture of asthma and anxiety," Williams said. "It's scary, really scary."

The Angels used Williams' roster spot to activate ace Jered Weaver, who made his return Wednesday night against the San Francisco Giants after missing three weeks with lower-back spasms.

Weaver was strong in his return, allowing two hits over six innings in a 6-0 victory. The right-hander walked two and struck out three before departing after throwing 78 pitches.

Williams will be replaced in the Angels' rotation by rookie Garrett Richards, who was 2-0 with a 0.86 ERA in three starts filling in for Weaver.

Williams said he's not sure how long it will be before he can pitch again. In July 2005, when he was with the Chicago Cubs, Williams left a game in St. Louis after gasping for breath. He said he has been plagued with asthma since he was 4 and has used an inhaler in the past.

Williams said he felt particularly nervous for Monday's start because it was against the Giants, who drafted him in the first round 13 years earlier. Williams said he never has been diagnosed with anxiety-related issues.

"I never thought I had that, shoot," Williams said.

Williams said he passed out as soon as he entered the Angels' clubhouse after his 3 1/3-inning outing, an eventual 5-3 loss to the Giants. He is scheduled for a stress test Thursday, but Williams said doctors have not indicated he could have an irregular heartbeat or other problem with his heart.

"There isn't any clarity, no," Angels manager Mike Scioscia said. "But we're just going to get direction from the medical department. He's got a lot of tests that are pending. We'll just move forward from there."