Castillo exited in the eighth inning of a loss to the Twins on Friday after taking a second foul tip off his mask. He's hitting .176 with three homers and 10 RBIs in 26 games this season.
In other moves, Chicago activated left-hander Manny Bañuelos from the injured list and recalled catcher Seby Zavala from Triple-A Charlotte. Bañuelos will start for the White Sox against the Twins on Saturday afternoon, and he has a 7.26 ERA in nine appearances this season, including five starts.
Zavala was hitting .218 with six homers and 18 RBIs in 21 games at Triple-A.