Los Angeles Angels right-hander Garrett Richards hasn't been cleared to resume throwing, and the team does not plan to activate him from the 10-day disabled list on Sunday when he's eligible to come off.

Richards was diagnosed with a strained right biceps last week. When doctors clear him to throw, Richards could need a minor league rehab assignment to build arm strength.

"They'll let us know when he's ready to pick up a ball," Angels manager Mike Scioscia told reporters on Thursday. "The longer he's out, obviously, there would be more rehab involved."

Richards missed most of last season because of a partially torn elbow ligament but chose rest and stem-cell injections over Tommy John surgery. He made it through spring training solidly but left his season-opening start at Oakland in the fifth inning on April 5 because of pain in his arm.

He won 28 games over the 2014 and 2015 seasons but was limited to six starts last year.

Right-handed reliever JC Ramirez will replace Richards in the rotation. He will start Friday against the Kansas City Royals.

Information from The Associated Press contributed to this report