 During the 2002 NRL season Blacklock was granted a release from his contract with the Dragons in order to play rugby union.Some speculate that this move was motivated by the disappointment Blacklock felt after not being selected for State of Origin, despite being the leading try scorer three years running.After a short stint playing rugby union with the New South Wales Waratahs, Blacklock returned to the Dragons during the latter half of the 2003 NRL season, where he again proved his worth by scoring 14 tries in 12 games.