Castillo will make his next start Sunday against the Padres, C. Trent Rosecrans of The Athletic Cincinnati reports.
Castillo wasn't initially in line for two starts heading into the current week, but the Reds' pitching schedule changed after Homer Bailey was banished to the bullpen following another poor outing Monday against the Diamondbacks. Bailey had been in line to start the series finale in San Diego, but that assignment will now fall to Castillo with the Reds taking advantage of Thursday's off day to get by with a four-man rotation for the time being. The adjustment looks like a favorable one for Castillo, who now has the luxury of facing an anemic Padres offense at one of the pitcher-friendlier environments in all of baseball.