ST. LOUIS _ Cole Hamels will make his Cubs debut Wednesday night with Tyler Chatwood heading to the bullpen.
"It's all about getting (Chatwood) well, getting him back to pitching like he can because that's going to benefit us for the next couple years," said manager Joe Maddon, who informed Chatwood of his demotion late Friday night.
Chatwood understood the decision.
"You never want that, but there's some stuff to do I need to work out," Chatwood said Saturday. "This will give me an opportunity to do that.
"Then hopefully when I start feeling good again, I'll get back in the rotation."
Left-hander Mike Montgomery will keep his spot and start Thursday night against the Padres.
Chatwood, in his first year of a three-year, $38 million contract, has walked 85 in 94 innings to go with a 4.98 ERA and is averaging less than five innings per start.
Chatwood admitted going to the bullpen will allow him to work on changes at a slower pace.
"It's hard to do that in the middle of the year and try to get big-league hitters out, especially for a first-place team," Chatwood said. "I need to go back to what got me here, what I signed here for and go back to being myself, and this will give me an opportunity to do that.
"I've been grinding all year. It hasn't been that fun, grinding that hard. But luckily we've been winning games in my starts, so that eases it. I'm excited to getting back to know what I can be."
Maddon didn't rule out the possibility of Chatwood rejoining the rotation. The Cubs have a stretch of 23 games without a day off starting Aug. 21.
Montgomery posted a 5.33 ERA in his first 18 relief appearances before moving to the rotation in place of the injured Yu Darvish and has a 3-3 record and 3.50 ERA in 11 starts.
Montgomery, however, is 0-2 with a 5.57 ERA in his last four starts. Opponents are batting .360 against him during that span.
"I'm going to put my head down, keep on top of my work and be there for the other guys and make sure when I'm out there I have my best," Montgomery said.
Montgomery has thrown 87 innings _ including his last 612/3 as a starter and is averaging 5.6 innings per start.
"It's open dialogue with me and them as far as how I'm feeling," Montgomery said. "You can get to that point where fatigue sets in and there are other factors. You're dealing with injuries here and that could make it worse.
"But from general fatigue, I'll be honest with them about how I feel, I'm on pace to throw more innings since the minor leagues. It's going to be open dialogue."
