In February 2006 he officially signed a developmental contract with Colorado Rapids, and was with the team until 2010.
During training on August 11, 2009, Clark injured his ACL, causing him to miss the remainder of the 2009 campaign. One year later, during a match against San Jose Earthquakes, Clark tore the same ACL, which again forced him to miss the remainder of the season.
During a nationally televised game against Seattle Sounders FC on March 23, 2012, sideline microphones picked up Clark's voice as he uttered an anti-gay slur at a ball boy who delivered him a ball for a throw-in situation. He apologized for the incident on Twitter several hours later.[4] On March 28, 2012, Major League Soccer suspended Clark for three games and fined him an undisclosed sum as punishment for the incident. League Commissioner Don Garber also ordered Clark to attend diversity and sensitivity training, stating, "Major League Soccer will not tolerate this type of behaviour from its players or staff at any time, under any circumstances," while also acknowledging that Clark had expressed "sincere remorse" for his actions. In response to the league's disciplinary action, Clark declared, "I am sorry about what happened during the Seattle match. I have personally apologized to the ball boy, and I want to take this chance to say I'm sorry to everyone that I've offended... what I said does not properly represent who I am or what I believe. I made a mistake that I truly regret. I accept the punishment that has been handed down by MLS."[5]