Baker said he wanted to give Rolen two days of rest, and it made more sense for him to face Jeff Karstens, who is scheduled to pitch Wednesday, than to have faced Tuesday's starter, James McDonald.
"McDonald throws a bunch of high fastballs, and [Karstens] is mostly a low-ball pitcher. I think that'd be easier on Scotty's shoulder, if he plays tomorrow versus today," Baker said. "We'll get him in there tomorrow. It's better for him and us to have another day."
Baker said shoulder soreness is not uncommon for Rolen, who has had several surgeries on his left shoulder.
"It's gonna be [sore]," Baker said. "It's gonna be probably until he retires."
Outfielder Jay Bruce also had a break Tuesday. Bruce and Rolen both represented the Reds at the All-Star Game, meaning they didn't get those days off like the rest of the team. Baker said he'd planned to rest both of them against the Pirates.
"I would have given them the day off when we came right back [from the All-Star break], except we were playing the Cardinals," Baker said.