Gray impressed in 2006 with TAC Cup club Oakleigh Chargers, kicking 56 goals. He also played for the Victoria Metro's under 18 side, in a team composed of fellow AFL draftees Bachar Houli, Matthew Kreuzer, Tom Hawkins and David Mackay. Despite this, Gray was not seen as a fancied draft option, due to his unfashionable style of play. His chances took a hit when he missed a draft camp due to injury. He did, however, attract interest from Port Adelaide after impressing their recruiters. Head recruiter at the time, Mick Moylan was impressed with his off-field discipline, with Gray maintaining an 8 and a half-hour job.
Subsequently, Gray was picked by Port Adelaide in the 2006 draft who used their fourth pick, becoming the 55th pick overall.