Jurrjens, 28, had been pitching for the Reds' Triple-A affiliate, the Louisville Bats. In six starts, he was 2-3 with an ERA of 4.46 and a K/BB ratio of about two to one. He has not played in a major league game since making two unremarkable appearances for the Orioles last season.
Jurrjens was an All-Star in 2011 with Braves, finishing the season with a 2.96 ERA and 1.224 WHIP.
In exchange for Jurrjens, Colorado sent first baseman Harold Riggins to Cincinnati. The 24-year-old Riggins was a seventh round draft choice by the Rockies in 2011 and was batting .263 for Double-A Tulsa this season.