It will be the first of possibly two starts.
"I didn't know if I was getting shut down or being sent to the Arizona Fall League or if I'd get back here," Butler said. "I was hoping to get a chance to come back here. I'm happy to be back here, so I can get more experience."
After being drafted out of Radford University 46th overall in 2012, Butler dominated in his first season and a half of his Minor League career, going 16-6 with a 1.91 ERA, and 198 strikeouts against 65 walks. Although his electric sinker went missing at the start of this season at Double-A Tulsa, he was effective enough to earn a June 6 callup. But after giving up six runs in 5 1/3 innings of a loss to the Dodgers, Butler went to the disabled list with the rotator cuff issue.
The rest of the year was spent trying to regain the sinker. He finished 6-9 with a 3.58 ERA at Tulsa. He also had brief rehab appearances at Triple-A Colorado Springs and Class A Advanced Modesto. In all, he was 6-10 with a 3.99 ERA in 20 starts. But Butler was able to pitch in Tulsa's run to the Texas League Championship Series, although he was the losing pitcher in Sunday's 5-0 loss in the series' final game at Midland.
"Hopefully he comes out on the other side better for it," Rockies manager Walt Weiss said. "He's had to make some adjustments this year, learn some new things, make some adjustments. That's not always a bad thing in the big picture."
Butler returns to the Rockies encouraged.
"My sinker is much closer than it was when I threw here last time," Butler said. "I had the confidence, but I knew something was not quite right.
"I learned to mix it up, try to keep guys off balance. It's helped make me better. I got through games where location, movement, velocity weren't there. Now I have things I can rely on other than the fastball."
Thomas Harding is a reporter for MLB.com. Read his blog, Hardball in the Rockies, follow him on Twitter @harding_at_mlb, and like his Facebook page, Thomas Harding and Friends at www.Rockies.com. This story was not subject to the approval of Major League Baseball or its clubs.