Walker (finger) is scheduled to throw a simulated game Tuesday, Carson Mason of MLB.com reports.
Manager Torey Lovullo noted Sunday that Walker has nearly recovered from a blister on his right index finger that forced him to the disabled list May 21, but the Diamondbacks are still proceeding cautiously with the 24-year-old so as not to irritate the finger. After throwing a successful bullpen session Saturday, Walker will be cleared to face hitters Tuesday before the Diamondbacks assess if he's ready to come off the DL. Randall Delgado entered the rotation in place of Walker last week and will make another start Monday against the Pirates, but Walker could be ready to go by the time his next turn in the rotation comes up.