Brisbane - Tenacious loose forward Liam Gill will reclaim his place on Australia's bench for their Rugby Championship clash in Brisbane later on Saturday after Jake Schatz was a late withdrawal due to a knee injury.
The 23-year-old Schatz had shown "signs of significant swelling" to his right knee, which had initially flared up after Friday's captain's run, the team said in a statement early on Saturday.
"Jake has come very close to debuting for Australia on a number of occasions now so on a personal level we are all extremely disappointed to rule him out on match-day," Wallabies coach Ewen McKenzie said.
"Liam has been involved in our opening two Tests so will slot straight back into what we are trying to achieve against the Springboks."
Gill, 21, played off the bench in the Wallabies' two opening losses of the southern hemisphere tournament against New Zealand.
Australia have already lost a number of forwards to injury in the series, including captain James Horwill, who was ruled out this week with a hamstring problem.
Scrumhalf Will Genia will lead the Wallabies at Suncorp Stadium in the lock's absence.
South Africa head into the match undefeated in the tournament after two wins against Argentina.
McKenzie also confirmed Waratahs lock Sitaleki Timani and backrower Dave Dennis would join the Australia squad in Perth on Sunday ahead of the Wallabies' clash with Argentina next week.
Teams:
Australia:
15 Israel Folau, 14 Nick Cummins, 13 Adam-Ashley Cooper, 12 Christian Lealiifano, 11 James O'Connor, 10 Quade Cooper, 9 Will Genia, 8 Ben Mowen, 7 Michael Hooper, 6 Scott Fardy, 5 James Horwill (captain), 4 Rob Simmons, 3 Sekope Kepu, 2 Stephen Moore, 1 James Slipper
Substitutes: 16 Saia Faingaa, 17 Scott Sio, 18 Ben Alexander, 19 Kane Douglas, 20 Liam Gill, 21 Nic White, 22 Matt Toomua, 23 Jesse Mogg
South Africa:
15 Zane Kirchner, 14 Willie le Roux, 13 JJ Engelbrecht, 12 Jean de Villiers (captain), 11 Bryan Habana, 10 Morné Steyn, 9 Ruan Pienaar, 8 Duane Vermeulen, 7 Willem Alberts, 6 Francois Louw, 5 Flip van der Merwe, 4 Eben Etzebeth, 3 Jannie du Plessis, 2 Bismarck du Plessis, 1 Tendai Mtawarira.
Substitutes: 16 Adriaan Strauss, 17 Gurthrö Steenkamp, 18 Coenie Oosthuizen, 19 Juandré Kruger, 20 Siya Kolisi, 21 Jano Vermaak, 22 Pat Lambie, 23 Jan Serfontein
The 23-year-old Schatz had shown "signs of significant swelling" to his right knee, which had initially flared up after Friday's captain's run, the team said in a statement early on Saturday.
"Jake has come very close to debuting for Australia on a number of occasions now so on a personal level we are all extremely disappointed to rule him out on match-day," Wallabies coach Ewen McKenzie said.
"Liam has been involved in our opening two Tests so will slot straight back into what we are trying to achieve against the Springboks."
Gill, 21, played off the bench in the Wallabies' two opening losses of the southern hemisphere tournament against New Zealand.
Australia have already lost a number of forwards to injury in the series, including captain James Horwill, who was ruled out this week with a hamstring problem.
Scrumhalf Will Genia will lead the Wallabies at Suncorp Stadium in the lock's absence.
South Africa head into the match undefeated in the tournament after two wins against Argentina.
McKenzie also confirmed Waratahs lock Sitaleki Timani and backrower Dave Dennis would join the Australia squad in Perth on Sunday ahead of the Wallabies' clash with Argentina next week.
Teams:
Australia:
15 Israel Folau, 14 Nick Cummins, 13 Adam-Ashley Cooper, 12 Christian Lealiifano, 11 James O'Connor, 10 Quade Cooper, 9 Will Genia, 8 Ben Mowen, 7 Michael Hooper, 6 Scott Fardy, 5 James Horwill (captain), 4 Rob Simmons, 3 Sekope Kepu, 2 Stephen Moore, 1 James Slipper
Substitutes: 16 Saia Faingaa, 17 Scott Sio, 18 Ben Alexander, 19 Kane Douglas, 20 Liam Gill, 21 Nic White, 22 Matt Toomua, 23 Jesse Mogg
South Africa:
15 Zane Kirchner, 14 Willie le Roux, 13 JJ Engelbrecht, 12 Jean de Villiers (captain), 11 Bryan Habana, 10 Morné Steyn, 9 Ruan Pienaar, 8 Duane Vermeulen, 7 Willem Alberts, 6 Francois Louw, 5 Flip van der Merwe, 4 Eben Etzebeth, 3 Jannie du Plessis, 2 Bismarck du Plessis, 1 Tendai Mtawarira.
Substitutes: 16 Adriaan Strauss, 17 Gurthrö Steenkamp, 18 Coenie Oosthuizen, 19 Juandré Kruger, 20 Siya Kolisi, 21 Jano Vermaak, 22 Pat Lambie, 23 Jan Serfontein