The Wallabies are expecting a ferocious Springboks side hell-bent on silencing critics when the teams battle at the South Africans' Ellis Park fortress tomorrow.
Stung by some intense criticism at home after sliding to four defeats in five Tri-Nations Tests, the World Cup holders will be playing for the pride of one of rugby's proudest nations.
"First and foremost (the Wallabies) have got to meet what's obviously going to come the other way and it's going to be significant," coach Robbie Deans warned.
"Last week we were able to deny early some of that pressure and that will be important again because there will be some significant challenges coming at us.
"If you don't cope with them then all of a sudden you've got a different contest.
"I suspect there will be a distinct approach and Ellis Park lends itself to that anyway."
Flanker Phil Waugh said the Boks would take no prisoners as they seek to protect a 45-year winning record over Australia in Johannesburg.
"Across the park they've obviously been very disappointing with the way they've gone over the last couple of games but it's their last hit-out in the Tri-Nations, it's Ellis Park, they'll throw everything at us," he said.
"We're certainly not reading too much into their last couple of performances. We know it will be a different team on Saturday afternoon and if we're not up for the game then they'll really put the sword into us."
Australia go into the game with five changes to their run-on side, including former league star Timana Tahu at inside centre.
They will need to overcome one of world rugby's most parochial crowds in the 60,000-seat stadium as well as the physical effects of Jo'burg's 1,700m altitude.
"If you are inaccurate and you turn over possession the opposition has the ability to move you from one end of the ground to the other a bit quicker and with greater ease," Deans said of the altitude issue.
"So you won't want to be turning over ball or ill discipline for that matter because it adds another 10 metres on the kicking range.
"Outside of that it's the same game."
The match has no bearing on the Tri-Nations title to be decided when Australia host the All Blacks in Brisbane on September 13.