The Giants traded Rosin, Nate Schierholtz, and Tommy Joseph to the Philadelphia Phillies in exchange for Hunter Pence on July 31, 2012. He played in 3 games for the Clearwater Threshers of the Class A-Advanced Florida State League at the end of 2012 and was then promoted to the Reading Phillies of the Class AA Eastern League. in 2013, where he was 9-6 with a 4.33 ERA in 26 games (23 starts).
