The Wallabies have suffered a huge blow in the lead-up to Saturday's Test against France, with veteran lock Nathan Sharpe ruled out of the match with a groin injury.
Sharpe was named in the starting XV on Tuesday, but injured his groin at training on Thursday and will be forced to watch the game from the sidelines.
The 28-year-old was given every chance to recover, but after being examined by the Wallabies medical team on Thursday night, it was decided he should be withdrawn.
"It's unfortunate but the injury is restricting Nathan, so the choice was made for us," Wallabies coach Robbie Deans said.
"We gave it as much time as we could, to allow it to settle but, with the game just two days away, we had to make the call and move on."
Waratahs utility forward Dean Mumm has been promoted into the starting line-up, while Queensland Reds flanker Hugh McMeniman will start on the bench.
Mumm will partner inexperienced Queensland Reds forward James Horwill in the second row and Deans believes the duo will perform well.
"The loss of Nathan obviously tests our depth, in terms of the Test experience our two locks have, but we've got total confidence in the guys who are there," Deans said.
"They've done the work on the training paddock and competed well in their Test careers so far. There's a great opportunity ahead for both of them."
Wallabies squad for second Test against France:
15. Adam Ashley-Cooper (ACT Brumbies)
14. Peter Hynes (Queensland Reds)
13. Stirling Mortlock (ACT Brumbies) captain
12. Berrick Barnes (Queensland Reds)
11. Lachlan Turner (NSW Waratahs)
10. Matt Giteau (Western Force)
9. Luke Burgess (NSW Waratahs)
8. Stephen Hoiles (ACT Brumbies)
7. Phil Waugh (NSW Waratahs)
6. Rocky Elsom (NSW Waratahs)
5. Dean Mumm (NSW Waratahs)
4. James Horwill (Queensland Reds)
3. Al Baxter (NSW Waratahs)
2. Stephen Moore