Ryu slid into home plate last Friday night against the Padres when he scored a run. When he threw before Tuesday's game he was still experiencing tightness and had limited use of motion.
"We're just being cautious, but no matter what the separation was in the standings right now, he wouldn't be pitching Friday. We would make sure he was right before he went out there," said Mattingly.
Ryu currently has a 3.02 ERA with a 13-5 record. The injury is not deemed to be serious nor long term, and expects Ryu to pitch against Arizona at Dodger Stadium on Wednesday.