Pena is starting at shortstop and batting sixth Saturday against the Twins, Brian McTaggart of MLB.com reports.
Pena hit atop the order in the Astros' first eight games of the season, but he'll move down the lineup after going 0-for-5 with four strikeouts Friday, which dropped his average to .171. Chas McCormick will bat leadoff Saturday as manager Dusty Baker tries to replace Jose Altuve (thumb) atop the lineup.