Pena (hamstring) is dealing with neck soreness following a collision with a runner during a rehab game Tuesday, Matt Kawahara of the Houston Chronicle reports.
Pena's neck prevented him from working as the DH in Double-A Corpus Christi's game Wednesday, but Astros manager Joe Espada didn't seem concerned about it becoming a long-term issue. The 28-year-old infielder is expected to return to minor-league action Thursday and could make his return to Houston's lineup sometime during the weekend series against Texas.