Key players David Pocock and Israel Folau handed Australia a double blow on Friday as both failed to prove their fitness and will miss the World Cup quarter-final with Scotland on Sunday.
Pocock, whose conversion to No.8 from flanker has been a roaring success, has been struggling with a calf injury suffered during the 15-6 Pool A victory over Wales last Saturday.
Fullback Folau struggled through the Wales game with a painful ankle, a knock he had picked up in the 33-13 whipping of hosts England a fortnight ago, and sees him miss his first Test for the Wallabies since he made his debut in 2013.
Pocock has been replaced by Ben McCalman with Kurtley Beale coming in at fullback for Folau.