The Wallabies have lost the services of back-row Wycliff Palu and lock Will Skelton due to injury for the rest of the Rugby World Cup.
Palu (hamstring) and Skelton (pectoral) both suffered injuries in Sunday’s match against Uruguay and scans on Monday confirmed the end of their respective England 2015 campaigns.
James Hanson (hooker) and Sam Carter (lock) have been called up to replace the injured duo.
Carter, who missed out on selection for Australia's 31-man Rugby World Cup squad due to a knee injury, is back to full fitness after recently joining Top 14 outfit Bordeaux-Begles on loan.
Hanson's call-up means that the Wallabies will now have three specialist hookers in the squad. The two others are captain Stephen Moore and Tatafu Polota-Nau.
One of the most respected players in recent times for the Wallabies, Palu’s Rugby World Cup ended when he was replaced at half-time against Uruguay, after missing the Wallabies opening match against Fiji though injury.
Skelton was substituted midway through the second half of that match with what was initially believed to be a shoulder injury but scan results on Monday showed he had sustained a pectoral injury.
The 23-year-old will consult a surgeon on his return to Australia.
Their replacements, Hanson and Carter, have had an active role with the Wallabies this international season and played in the Test against the USA in Chicago earlier this month.
Hanson has 10 Wallabies caps, having debuted in the 2012 Bledisloe Cup Test at Suncorp Stadium, while Carter has donned the gold jersey 12 times since debuting in 2014.
Both players will join the squad looking for their maiden Rugby World Cup appearance.
Wallabies head coach Michael Cheika said it was disappointing to see the tournament end for Palu and Skelton after solid contributions by the pair throughout the international season.
“Very few players have the opportunity to play for the Wallabies, let alone at a Rugby World Cup, so from that perspective I’m really gutted for them," said Cheika.
“From a team perspective, they both play important roles in the side and it is disappointing that we need to replace players in our squad.”
Cheika said he had complete faith in Hanson and Carter to fill the void left by the duo for the remainder of the tournament.
“Both James and Sam have been part of the team at various stages this season and I am confident they will be able to step up and grasp the opportunity they have been given.”