Waldichuk underwent Tommy John surgery on his left elbow Wednesday, Martin Gallegos of MLB.com reports.

Waldichuk will undergo left elbow surgery Wednesday, Martin Gallegos of MLB.com reports.

Waldichuk (elbow) will visit with Dr. Neal ElAttrache on Monday, Martin Gallegos of MLB.com reports.

Waldichuk (elbow) experienced a setback after throwing a 25-pitch live batting practice April 29 and is shut down for the time being, MLB.com reports.

Waldichuk (elbow) threw 25 pitches against live hitters Monday, Martin Gallegos of MLB.com reports.

Waldichuk (elbow) threw a successful 30-pitch bullpen session Tuesday, MLB.com reports. "Waldichuk looked really good and got his velocity up from his last bullpen," said A's manager Mark Kotsay. "He's trending in the right direction."

Waldichuk (elbow) could begin a rehab assignment sometime next week, Martin Gallegos of MLB.com reports.

Waldichuk (elbow) threw a 20-25 pitch bullpen Friday, the Associated Press reports.

Waldichuk (elbow) threw a bullpen session Monday that went off without any setbacks, Jason Burke of SI.com reports.

Waldichuk (elbow) will throw a bullpen session Wednesday, Martin Gallegos of MLB.comreports.