A's left-hander Felix Doubront will undergo Tommy John surgery on his throwing elbow Tuesday and miss the rest of the season.
The team and pitcher knew surgery was a possibility but Doubront traveled to Cincinnati to see Dr. Timothy Kremchek for a second opinion Monday. An MRI review showed that Doubront requires reconstruction of the ulnar collateral ligament.
Doubront, who won the fifth starter job out of camp, left his final exhibition start against the Giants on April 2 with tightness in his forearm.
Eric Surkamp is due to make his second start in the No.