Melbourne - Wing Adam Ashley-Cooper and No 8 Wycliff Palu will miss the Wallabies' Rugby Championship clash against Argentina on the Gold Coast on Saturday due to injuries.
Ashley-Cooper has been ruled out for one week with an ongoing nerve compression injury to his neck, which was exacerbated in the tight win over South Africa in Perth at the weekend, the team said in a media release on Monday.
Palu suffered a head knock on the weekend and would follow concussion protocols ahead of his return to play, the release added.
"It's disappointing to lose two experienced members of our squad ahead of what is an extremely important game against Argentina," Wallabies coach Ewen McKenzie said.
"However, this year we've taken a proactive approach to making early decisions around guys carrying injuries, which is the case here. As is always the case with sport, the next guy in line now gets a chance to step-up and take advantage of the opportunity they'll be given."
Reds No 8 Jake Schatz comes into the Wallabies camp as an additional training squad member, joining scrumhalf Will Genia, hooker Saia Fainga'a and prop Benn Robinson, the team said.
Australia are third in the four-nation championship standings after three rounds, four points ahead of Argentina, who remain winless.