Astros manager Joe Espada said after Monday's 5-4 loss to the Twins that Pena has been diagnosed with a mild left calf strain and will be placed on the 10-day injured list, Chandler Rome of The Athletic reports.
Pena was held out of the starting lineup Monday after experiencing left leg discomfort, and Espada revealed after the game that further testing revealed a calf strain. Espada noted that he's hopeful Pena will be in line for a minimum-length stint on the shelf, which would put the shortstop in line to return July 10 against the Rangers. Look for Nick Allen and Brice Matthews to see most of the reps at shortstop in Pena's absence.