DENVER -- Rockies right-hander Eddie Butler will make his first rehab assignment Saturday with Class A Advanced Modesto as he works his way back from right rotator cuff inflammation.
Butler is set to throw 60 pitches in Modesto against Bakersfield following his successful 45-pitch simulated game session on Tuesday.
The Rockies want Butler to make at least two rehab starts with the second coming on July 17 for Triple-A Colorado Springs. He's tentatively scheduled for 75-80 pitches that day. If all goes well, he would be in line to start again on July 22, which is when the Rockies first require a fifth starter out of the All-Star Break.
Butler has been out since feeling an unusual level of soreness in his throwing shoulder after his Major League debut on June 6. He's also been battling a blood blister that first appeared on July 5 during his live batting practice session against Carlos Gonzalez.
Butler expects the blood blister to be a "constant thing" but he's continually had it drained and hasn't missed any of his rehab steps while dealing with it.
The Dodgers got to Butler for 10 hits and six earned runs across 5 1/3 innings during his Major League debut last month. Before that, Butler held a 2.62 ERA across 68 2/3 innings at Double-A Tulsa with 40 strikeouts against 19 walks.
Cody Ulm is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.