Pena was removed from Saturday's game against the Orioles due to an apparent leg injury, Matt Kawahara of the Houston Chronicle reports.
Pena was visited by one of the Astros' trainers after taking a swing in the third inning, and he appeared to be having problems with his right leg. He was able to stay in and complete the at-bat but was replaced on defense to begin the fourth. The severity of his injury remains unknown, but the Astros may offer an update in the near future.