[citation needed] Mitchell made his international debut for the Wallabies against South Africa in 2005,[6] after being selected after a season with the Queensland Reds in which he scored 11 tries and was named Australia's rookie of the year.

By this time Mitchell had switched to newly formed Western Force and impressed enough to gain a place in the Australia squad for the 2007 World Cup in France.

[1] Mitchell's domestic future again had a period of speculation when he was approached by the NSW Waratahs and the ACT Brumbies ahead of the 2010 Super Rugby season.

[citation needed] Mitchell dislocated his ankle and broke a bone in his leg after he collided with Scott Higginbotham of the Reds during their match on Saturday, 23 April and was initially ruled out of the 2011 Rugby World Cup.

In the lead up to the 2012 Super Rugby season Mitchell suffered an ankle problem, and missed the Waratahs pre-season games.

[16] In February 2022, Mitchell participated in a charity match at Suncorp Stadium to raise funds for Tonga after a tsunami devastated the island nation.