In the television series Alias (2001–06), Cooper achieved some success with the role of Will Tippin, a local reporter for a newspaper and the best friend of Jennifer Garner's character, Sydney Bristow. Garner was one of the first people he met in Los Angeles and was, in Cooper's words, "very maternal . . . She wanted to take care of me, make sure I was okay all the time. " He acted in the 2002 psychological thriller Changing Lanes. The scenes in which he appeared were edited out of the final cut of the film, but are featured on the film's DVD and Blu-ray releases. Also in 2002, he played a man involved in a love triangle in the romantic drama Bending All the Rules. He guest-starred in the short-lived TV series Miss Match and played the role of cowboy and race horse trainer Morgan Murphy in the television film The Last Cowboy, which aired on the Hallmark Channel in January 2003. He later appeared in the television film I Want to Marry Ryan Banks (2004) with Jason Priestley and as a regular guest star in the WB series Jack & Bobby (2004–05).