Gallen exited Friday's game against the Giants with an apparent leg injury, Steve Gilbert of MLB.com reports.
Gallen appeared to hurt his leg during a delivery in the top of the third inning, and he was immediately removed from the game after visiting with a trainer. Prior to his departure, he allowed three runs on five hits and three walks while striking out three in two innings. It's not yet clear what injury he could be dealing with or whether the issue will force him to miss his next turn through the rotation.