Sydney - Wallabies back Matt Giteau will miss this week's Rugby Championship Test in Argentina with a sternum injury picked up against South Africa, the Australian Rugby Union said on Monday.
Chest scans cleared Toulon-based Giteau of any serious damage after Saturday's game against the Springboks but team officials said they have opted to rest the 32-year-old for the next stage of the tournament.
"I know how desperate Matthew was to play and continue to contribute to this group over the next week, his leadership and presence off the field will be missed," Wallabies coach Michael Cheika said.
"It's disappointing to lose him for this round. However, knowing he will be right to go for the Bledisloe series (against New Zealand) is reassuring for the group and our fans.
"In the end, the decision sits with me. It's going to be a big year for Gits and to send him over to Mendoza after a very physical Test as well as a tight turnaround, just isn't fair on him or the group."
The exclusion of Giteau from the 31-man squad to Mendoza makes way for the return of Brumbies playmaker Christian Leali'ifano, who is back after being used as an additional training squad member only in the lead-up to the Springboks Test.
"For the Wallabies to be successful, we need to have the belief that our depth can cover each position and I have that confidence in Christian if he's called upon for this weekend's match," added Cheika.
Nick Cummins and Nic White were also added to the squad on Sunday following injuries to Will Genia and Rob Horne.
There were two further additions in hooker James Hanson and prop Tetera Faulkner, following Australia's last-gasp 24-20 victory in Brisbane on the weekend.