Petke, a three-time MLS All-Star, was traded to D.C. United with a draft pick and an allocation for Eddie Pope, Jaime Moreno, and Richie Williams. He won the MLS Cup with DC during the 2004 season. Petke was then traded to Colorado Rapids in May 2005 in a three-team deal. He helped stabilize the Colorado backline and was a key player in helping the Rapids reach the Western Conference Finals in 2005. He remained a fixture in the heart of the Rapids defense for the next three years.