A St Clair Comets junior, McKinnon made his first grade début with the South Sydney Rabbitohs in 2002 following their re-admittance into the competition.

In a Round 19 match in 2007, McKinnon was sent off by referee Paul Simpkins in the final minute of play for allegedly kneeing Taniela Tuiaki.

McKinnon was ruled out of most of the 2008 NRL Season after an injury in the Warriors first trial game against the Newcastle Knights left him requiring a knee reconstruction.

[6] After struggling to break into the Warriors 2010 team as he failed to regain his speed from his knee injury, McKinnon signed for the Wests Tigers on 26 May 2010.

[8] McKinnon began the 2011 season as the starting fullback for the Wests Tigers, but hampered by injuries, lost his position to Tim Moltzen.