OAKLAND, Calif. -- The Oakland Athletics designated first baseman Eric Karros for assignment on Tuesday.

The A's also activated left-hander Chris Hammond from the 15-day disabled list. He's been out since June 12 with a strained left shoulder.

Oakland has 10 days to trade Karros, release him or assign him outright to the minors. He was told late Monday by general manager Billy Beane about the decision.

"I hope he winds up getting in a situation where it works out," manager Ken Macha said. "It's a tough year with our other two guys both having tremendous years."

Karros, 36, struggled in his first season with the A's, batting .194 with two homers and 11 RBIs while starting just 24 games. The 14-year veteran signed with Oakland last February after 12 seasons in Los Angeles and one season with the Chicago Cubs.

Karros has a .268 career average with 284 homers and 1,027 RBIs.

Hammond believes he's finally healthy. He'd had no previous arm problems in his career.

"I'm looking forward to finally sitting out in the bullpen," he said. "I feel good. I'm just glad it happened in the middle of the season and not the end. Hopefully I can help the team in the second half."