 McCabe helped the Warringah Rats to the semi-finals of the 2008 (NSW) Shute Shield competition, before signing for the Brumbies in 2009.In 2009 he was selected for the Brumbies academy squad, and after impressing on a development tour to France in mid 2009, where he was the Brumbies 'Player of the Tour', he signed a full contract with the franchise for the 2010 Super 14 season.In his debut season, he played every minute of every game that season, the only Brumby to do this, making his Super 14 debut against the Western Force on 12 February during Round 1, where he established himself on the right wing (#14).