To make room on the 25-man roster Wednesday, the Rockies optioned righty Rob Scahill to Colorado Springs.
The 23-year-old Chatwood was 1-0 with a 1.84 ERA with 17 strikeouts and four walks in three starts with Colorado Springs this season. In 2012, Chatwood was the youngest member of the Rockies' opening day roster and finished the season 5-6 with a 5.43 ERA in 19 games, including 12 starts.
He is 11-17 with a 4.97 ERA in 46 appearances — 37 starts — in his major league career.
Scahill was recalled April 21 and pitched three scoreless innings in the first game of a doubleheader against Atlanta on Tuesday.
Copyright 2013 The Associated Press.