Jered Weaver understands the importance of September baseball, but he's more intimate with how his right arm should feel.

"I can't keep going at 75 to 80%," Weaver said Friday, making his first comments since an MRI exam this week revealed biceps tendinitis that forced him from Friday's scheduled start against the Detroit Tigers. "I needed some time off."

How much remains uncertain.

Angels Manager Mike Scioscia wouldn't discount the idea of Weaver returning next week against the Oakland Athletics.

"He'll have to … let it calm down," Scioscia said.

With just 24 games remaining after Friday's, Weaver (16-4, 2.86 earned-run average) could conceivably make five more starts on four days' rest if he returned Tuesday against Oakland.

He said his discomfort at the front of his shoulder dates to his nine-strikeout complete game Aug. 6 in Oakland.

"It's been lingering ever since," Weaver said. "I've pitched through this before. I'd do the treatment. But when it feels like it was getting better, I would have to throw 100 to 120 pitches and it sets me back again."

Weaver is 2-3 since Aug. 6, giving up an uncharacteristic nine earned runs in three innings Aug. 17 against Tampa Bay.

The tightness restricted him from throwing his best slider and decreased his fastball velocity. He's taking anti-inflammatory medication and will undergo treatments of stretching and massages.

He said an MRI exam performed Wednesday followed by an examination by team orthopedist Lewis Yocum showed "normal wear and tear." The prescription: "Rest it, and hope to get back out there as soon as possible."