Castillo was removed from Saturday's Cactus League game against the Rockies due to left adductor tightness, Alex Weiner of ArizonaSports.com reports.
Castillo went down after trying to catch a wild throw from Jordan Lawlar on a play at first base. The severity of Castillo's injury isn't immediately clear, but the Diamondbacks will likely give him at least a few days to recover before deploying him in another exhibition game.