DETROIT -- Mike Sweeney knows his major-league career might be over.
The Oakland Athletics released the 35-year-old first baseman-designated hitter on Tuesday after he struggled to return from operations on each knee.
Sweeney, a 14-year veteran who spent all but this season with the Kansas City Royals, was limited to 42 games this year because of knee injuries. Doctors have told the five-time All-Star he needs surgery on both knees and the recovery time is six to nine months.
Sweeney had procedures in early June to repair loose cartilage in the knees. He had hoped to recover by the All-Star break.
"If this is it, I will always be proud, man," he said. "If I can come back and play, it will be that much better."
Sweeney has a .299 batting average with 199 homers and 849 RBIs in 1,324 games. After signing a minor-league deal with the A's before spring training, he batted .286 this season with two home runs and 12 RBIs.
He has been hampered by injuries the past eight seasons. The last year he played in more than 126 games was 2001.
Sweeney has a $500,000 base salary, earned a $250,000 bonus for being active 30 days and needed eight more days on the active roster to reach 75 and earn another $250,000 bonus.
He wasn't bitter but did say: "Do I agree with it? Absolutely not. It's a horrible decision ... but I understand it's a business decision."
Despite Sweeney's injuries this season, A's manager Bob Geren appreciated his presence as a clubhouse leader.
"He's definitely been a positive influence on the guys," Geren said.
Oakland replaced Sweeney on the roster by purchasing the contract of third baseman Jeff Baisley from Triple-A Sacramento, where he hit .298 with nine home runs and 44 RBIs in 81 games.