Australia have lost second row Rob Simmons for both Bledisloe Cup matches against New Zealand because of a wrist injury.
The Reds lock requires surgery on his scaphoid and will miss the Rugby Championship decider in Sydney, as well as the return fixture against the All Blacks in Auckland a week later.
He is however expected to make a full recovery in time for the Wallabies' World Cup warm-up game against the USA in Chicago next month.
Michael Cheika will not add any players to his squad for this weekend's game, but admits losing Simmons, who had started both games so far in the Rugby Championship, was a blow.
"Obviously we’re all disappointed to lose Rob," said Cheika.
"However, we’re confident he will make a full recovery ahead of Rugby World Cup.
"We’ve been able to build some real depth in the lock position, and Rob's injury presents an opportunity for another player in the squad to stake their claim."