Defeats to New Zealand in the first two matches of their campaign - the second a humbling 22-0 shutout in Auckland - have left the Wallabies reeling and coach Robbie Deans once again living on borrowed time.
The gritty New Zealander is not one to back away from a fight but there can be little doubt that a record fifth successive win over the Springboks is the minimum expected by a demanding Australian public.
South Africa have won three and drawn one of the six Tests against Australia in Perth but, after their disappointing 16-16 draw against the Pumas in Mendoza, new coach Heyneke Meyer is also feeling the pressure.
"They're similar to us, they want a result out of this game," Deans said earlier this week.
"They would have been frustrated with their last outing, so both sides will be pretty keen."
Australia have lost key players like captain James Horwill, flanker David Pocock and back James O'Connor to injury but more concerning, perhaps, has been the form of fly-half Quade Cooper and full-back Kurtley Beale.
Cooper was the inspiration behind Australia's triumph in the curtailed Tri-nations last year but he has not had nearly the same impact since returning from the knee injury that ended his World Cup.
Beale is one of the most exciting backs in the world when on song but had a miserable outing in the 27-19 defeat to the All Blacks in Sydney and was dropped to the bench for the Eden Park defeat.
Deans is backing both to fire in Perth, however, and selected a team built for speed.
Queensland Reds flyer Dom Shipperley will make his debut on the wing while number eight - and occasional winger - Radike Samo has been brought into the back row.
The Springbok team will be looking to stop the supply of ball to the Australian backs and Meyer's team selection suggested there would be little change to his tactics of a big physical presence up front with plenty of tactical kicking.
Powerful number eight Duane Vermeulen will make his Test debut in a big back row but the only specialist openside flanker in the squad, Francois Louw, will start on the bench.
Alongside him in the replacements will be 20-year-old fly-half Johan Goosen, who has a hefty kick but also the ability to surprise in attack, and talented young full-back Pat Lambie.
Meyer, whose team won their opener over Argentina in South Africa, will be looking for much improved execution from his side and a little more luck than they had when they lost to Australia in the World Cup quarter-finals last year.
"The challenge that lies ahead is a massive one," Meyer said on arrival in Western Australia.
"We've not beaten Australia in our last four matches and have won only one out of our last seven encounters against them. I have a lot of respect for Robbie Deans's coaching and they have a very good squad.
"We also realise we were not good enough against Argentina in Mendoza and we have to improve a lot if we are going to be competitive on Saturday."
Australia: 15-Kurtley Beale, 14-Dom Shipperley, 13-Adam Ashley-Cooper, 12-Berrick Barnes, 11-Digby Ioane, 10-Quade Cooper, 9-Will Genia (captain), 8-Radike Samo, 7-Michael Hooper, 6-Dave Dennis, 5-Nathan Sharpe, 4-Sitaleki Timani, 3-Ben Alexander, 2-Stephen Moore, 1-Benn Robinson.
South Africa: 15-Zane Kirchner, 14-Bryan Habana, 13-Jean de Villiers, 12-Francois Steyn, 11-Francois Hougaard, 10-Morne Steyn, 9-Ruan Pienaar, 8-Duane Vermeulen, 7-Willem Alberts, 6-Marcell Coetzee, 5-Juandre Kruger, 4-Eben Etzebeth, 3-Jannie du Plessis, 2-Adriaan Strauss, 1-Tendai Mtawarira.
Referee: Nigel Owens (Wales)