Oakland Athletics pitching prospect A.J. Puk (elbow) had successful Tommy John surgery on Tuesday, according to Susan Slusser of the San Francisco Chronicle. In spring training, Puk was looking good and was competing for a starting rotation spot. He had a 3.38 ERA in 10 innings with seven strikeouts. Puk is expected to miss 12 to 18 months, so he should return around the middle of 2019. While most have been successful in recovering from TJ surgery, there is still risk. Puk is a good prospect and should only be held onto in deep dynasty leagues.