Sweeney was placed on the 15-day disabled list Monday with right patella tendinitis. Noted surgeon Dr. Richard Steadman of Vail, Colo., will perform the operation as soon as possible. Sweeney is expected to be fully recovered by spring training.
"It got to a point where it was very painful for him," manager Bob Geren said. "It was recommended that to go on in the future and to feel 100 percent healthy, this was the right way to go."
Sweeney was batting a team-leading .294 with one homer, 20 doubles and 36 RBIs this season. He had gone 54 games without a home run. Sweeney had been trying to play through the pain before deciding to have surgery.
"We've had guys injured and banged up," Geren said. "What he had done to play through this was very commendable. He's a very tough guy. He's done a heck of a job. We appreciate what he has done."
Oakland recalled right-hander Henry Rodriguez to take Sweeney's spot on the roster. Rodriguez is starting his fourth stint with the A's this season. He has a 3.86 ERA in seven relief appearances.
Also, left-hander Brett Anderson is scheduled to make a rehab start for Triple-A Sacramento at Colorado Springs on Tuesday night. Depending on how the start goes, Anderson could return to the A's rotation next week.