Pittsburgh Pirates right-hander Jeff Karstens is expected to miss another 10-12 weeks after having shoulder surgery on Friday, the Pittsburgh Post-Gazette reported.
Karstens has been out all season due to right shoulder inflammation. He was shut down after making two minor league rehab starts in May.
He opted to have rotator cuff and labrum surgery.
Karstens was 5-4 with a 3.97 ERA and a 1.15 WHIP in 90 2/3 innings last year, including 15 starts and four relief outings.