Perez (triceps) was still sore Tuesday, and will see the doctor again either Tuesday or later on this week, Kevin McAlpin of 680 The FAN reports.
Perez left Monday's start against the Padres after giving up six earned runs during 4.1 innings on the mound. He will be further evaluated before his next scheduled start arrives, which would land on Saturday. If Perez is unable to go, Casey Kelly or Aaron Blair could toe the rubber against the Cubs.