Pomeranz undergoes shoulder surgery

A's left-hander Drew Pomeranz underwent successful clavicle resection surgery on his throwing shoulder this week, the club announced Thursday.

Pomeranz is expected to endure a six-week recovery period -- standard for such an operation, which was performed in Dallas by Dr. Keith Meister -- and be ready by Spring Training.

The southpaw pitched through shoulder issues for much of the season before being shut down in September. He posted a 2.61 ERA in 44 relief appearances compared to a 4.63 ERA in nine starting assignments and will be considered for both roles come Spring Training.