After being overlooked in the National Draft, Betts was recruited to the AFL with pick 3 in the 2004 Pre-Season Draft by the Carlton Football Club. He attracted attention as a lively small forward during the 2005 pre-season, and made his AFL debut in round 1 against the . He kicked 19 goals in 19 games in 2006, playing as a permanent small forward and becoming a fan favourite. The next year, Betts won the Goal of the Year for his goal in round 21 against , a banana kick from the boundary under pressure.