"I know that he'd been killer last year and then this year it's not been as lights out," Cubs manager Joe Maddon said. "I heard things were getting better -- that's what I was told. I know he's got a big arm with really good stuff. You'll see him, I'll try to get him in there as quickly as possible. But there's definitely a ceiling with this guy if he gets it all back together. I'm curious to see it, too."
Rosscup, 27, had trouble getting loose before his most recent appearance on Tuesday and exited the game due to tightness in the shoulder after allowing an earned run on two hits and a walk. He owns a 4.30 ERA in 26 outings this season.
"We're not anticipating anything elongated or anything serious," Maddon said. "It's just something that needed to be quieted down, and the only way to do that is rest."
Montero tried to get loose before Wednesday's game, but he eventually approached Maddon and the two decided to give him a day of rest, though mostly as a precautionary measure. David Ross started in his place behind the plate.
"I anticipate [Montero] being able to pinch-hit tonight if we need him to," Maddon said. "It's one of those things where in September he would probably play, but he's a little bit stiff so we said no, let's just do it this way."
If Montero's injury were to linger, Maddon still doesn't anticipate recently promoted prospect Kyle Schwarber getting any starts behind the plate.
"Not unless we absolutely had to," Maddon said. "If it was a moment that we had to do it, then you do it. And then you try to make it work. But David Ross is a really good receiver, he knows what he's doing, he knows the pitchers, he knows the other team's hitters well, and that matters a lot. If [Schwarber] is pressed into service, then yes, but I'm not looking for a spot to make him start."
• On Thursday, crews will move the historic caretaker's house back to its original location at the northwest corner of Wrigley Field. Last November, the house was moved to a parking lot to allow crews to complete changes needed inside Gate K as part of the renovation project at the ballpark.
• Former Cubs pitcher Kerry Wood will host a "Battle of the Bats Home Run Derby" at Wrigley Field on Thursday. Participants will take swings against Wood and some of his former teammates in a day-long hitting challenge. The participants will receive instructions on fielding and hitting, a full uniform, a tour of the ballpark, and a post-event party. All proceeds benefit the Wood Family Foundation and Cubs Charities.