Ben McCalman has been ruled out of Australia's final Test against England after fracturing a shoulder blade.
The No 8 suffered the injury after coming off the bench during a 23-7 defeat in Melbourne that gave England a 2-0 lead in the three-match series.
McCalman has been ruled out for six weeks, and Leroy Houston has been called into the squad for Saturday's Sydney game.
David Pocock started the series at No 8 but fractured an eye socket in the opening Test, and Michael Cheika used flanker Sean McMahon in the role in Melbourne.
Wycliff Palu is an option this weekend if Cheika chooses to revert to a specialist.