Ackles worked steadily throughout 2003. He joined the cast of the WB's hit show Dawson's Creek during its final season, playing CJ, Jen Lindley's lover. Afterward, Ackles filmed several episodes of the unaired series Still Life for Fox before it was abruptly dropped. He also had a small role in the 2004 short film The Plight of Clownana. Ackles was the producer's first choice to play Eliza Dushku's love interest on the second season of Tru Calling; Ackles turned down the role, which was then offered to Eric Christian Olsen and the character's name was changed to "Jensen" because the producers of Tru Calling liked Ackles' name. Ackles returned to Vancouver (where Dark Angel was filmed) in 2004 to become a regular on Smallville playing the assistant football coach Jason Teague, who was also the newest romantic interest for Lana Lang (played by Kristin Kreuk). He also had a lead role in the 2005 film Devour in which Ackles' father, actor Alan Ackles, also had a role playing the father of Ackles' character, Jake Gray.