Williams began feeling out of breath while in the clubhouse after his outing against the Giants, when he gave up four runs in 3 1/3 innings of an eventual 5-3 loss, and outfielder Torii Hunter heard he passed out before paramedics came in.
Williams stayed overnight at a nearby hospital to undergo more tests, but the club believes he'll be fine.
- 142 wins
- 110 wins
"I think he's feeling much better right now than he did when he left," Angels manager Mike Scioscia said, "but obviously we have to just take it one step at a time and hopefully it's not going to be anything serious."
Scioscia had no reason to believe Williams was fighting shortness of breath while pitching against a Giants team he began his career with. The 30-year-old right-hander, the club believes, started feeling dizzy when returning to the Angels clubhouse after a 75-pitch outing, his teammates getting word on the bench from athletic trainers around the fourth inning.
"It was tough to hear," Hunter said. "We didn't know what was going on. We knew he passed out in the locker room. All you can do is just say a little prayer at that point, and hopefully he's doing OK."
"I think we felt much better right now because he's resting comfortably, and I think he's settled down a little bit," Scioscia added. "We'll hopefully get some more information tonight."
Alden Gonzalez is a reporter for MLB.com. Read his blog, Gonzo and "The Show", and follow him on Twitter @Alden_Gonzalez. This story was not subject to the approval of Major League Baseball or its clubs.