"I've been anticipating his arrival at the big league level and we'll see it Friday night. He's a young kid with a big arm. There's a lot of on-the-job training to be done -- for anybody -- but certainly he's a younger, talented kid."
A supplemental first-round Draft pick chosen 46th overall in 2012 out of Radford University, Butler is 4-4 with a 2.49 ERA in 11 starts at Double-A Tulsa. The Rockies declined to immediately make an official announcement, but Butler will take the spot of left-hander Franklin Morales (3-6, 6.03 ERA in 12 games, 11 starts) in the Rockies' rotation.
Butler, who turns 23 on June 13, entered the season with a 1.91 ERA in 41 professional games at the Rookie, Class A and Double-A levels. Last year, he had an organization-best 1.80 ERA in 28 starts at Class A Asheville, Class A Advanced Modesto and Tulsa. The Rockies invited him to Major League Spring Training, where he went 0-0 with a 3.86 ERA in three games covering seven innings.
Butler entered the season the as the No. 33 prospect in the Minor Leagues as ranked by MLB.com.
Butler's work this season at Tulsa has ranged from strong to outstanding, with the exception of his most recent start. He had not given up an earned run in three starts covering 19 2/3 inning before giving up seven hits and two walks and lasting 4 2/3 innings, with three runs (two earned) against Midland on Saturday.
The Rockies are in need of rotation help.
Morales, a reliever for most of his career with the Rockies and Red Sox, won a rotation job coming out of Spring Training, but as he struggled he remained in the rotation out of necessity with left-hander Brett Anderson (broken left index finger) and right-hander Tyler Chatwood (strained right flexor tendon) on the 60-day disabled list.
Morales has been plagued by the walk (26 in 43 innings) and the home run (13). However, he could move to the bullpen. On Tuesday, the Rockies began a 10-game homestand and the team often increases its bullpen by one for lengthy stints at Coors Field. He could be serviceable against left-handed batters, who are hitting .250 with three home runs in 84 plate appearances against him.
Weiss said Morales was available out of the bullpen Tuesday night.