New York Yankees pitcher Michael Pineda has undergone season-ending shoulder surgery, the team announced Tuesday. Pineda, whom the Yanks obtained in an off-season trade with Seattle, had an anterior labral tear in his right (throwing) shoulder. Dr. David Altchek, assisted by Yankees team physician Dr. Christopher Ahmad, performed the anthroscopic procedure at the Hospital for Special Surgery in New York. The 23-year-old has been on the disabled list since spring training with tendinitis in his throwing shoulder. He allowed 12 runs on 24 hits and 10 walks in 19 innings during the pre-season. Pineda made the all-star team with the Mariners in his rookie season last year, when he went 9-10 with a 3.74 ERA in 28 starts.