"They've been punishing me with exercise," said Butler, laughing. "No, they're just running me through all the strengthening for the chest, back, scaps and all that shoulder stuff.
"I was doing a good number of them, but not all the stuff I'm doing now. So there's definitely some extra stuff that I haven't done before."
Butler, who made a meteoric rise to the Majors after being drafted 46th overall in 2012, experienced unexpected soreness in his right rotator cuff after his Major League debut on June 6, when he gave up six runs in 5 2/3 innings in a loss to the Dodgers.
Butler seemed to be on the way back quickly. He threw at 140 feet and even threw off the slope of the mound last Monday at Dodger Stadium. But at the behest of his agent, Butler received a second opinion from Dodgers physician Dr. Neal ElAttrache, who found the same weaknesses the Rockies' doctors saw. After a consultation, the Rockies and Butler agreed to back off from throwing to address the muscle weaknesses.
Rockies head athletic trainer Keith Dugger said the pain served as a warning signal that Butler had not learned all he needed about between-starts maintenance during his quick Minor League time. Butler is less than two seasons from throwing once a week in college, as opposed to every five days as a professional. Because of his success in the Minors, he didn't diversify his between-starts routine and that eventually caught up to him.
"This is what his maintenance should be," Dugger said. "He was just young and didn't know. Sometimes good things happen when a guy goes on the shelf for a while. They learn that the routine they got away with when they were amateurs or early professionals doesn't work when you get up here, so you have to help educate them.
"It's not just when you're hurt. It's a preventative measure. It's the same as brushing your teeth every day. That's what you teach, how to get a routine."
Thomas Harding is a reporter for MLB.com. Read his blog, Hardball in the Rockies, and follow him on Twitter @harding_at_mlb. This story was not subject to the approval of Major League Baseball or its clubs.