The Astros removed Pena from the game after fouling off a pitch mid-at-bat, reports Julia Morales of Space City Home Network.
Brice Matthews replaced Pena at shortstop in the sixth inning after fouling off a pitch in the middle of his at-bat. The shortstop left the game with a trainer after going 1-for-2 with two stolen bases and a run scored. Houston has yet to announce the specificity of the injury Pena suffered.