The chastened Wallabies will be searching for their first title in a decade and the decimated Springboks are out to prove they are serious contenders when the Tri-Nations tournament kicks off in Sydney on Saturday.

Both southern hemisphere giants have the motivation to prove their critics wrong in the 16th edition of the Tri-Nations, also involving New Zealand, and their final major series of internationals before September's World Cup.

The Wallabies were embarrassed 32-23 by Samoa last Sunday in what has been described as their worst-ever defeat, while the world champions South Africa left 23 injured players at home for their away leg in the Tri-Nations - while lock Johann Muller was a late withdrawal from the side on Thursday.

The Springboks have named three debutants and another six have 10 Test caps or fewer in the starting line-up, to be led by 102-Test World Cup winning hooker John Smit.

Wallabies coach Robbie Deans, under fire for fielding an unbalanced line-up against the physical Samoans, has reacted by bolstering his starting XV with seven big guns missing from last weekend's Sydney humiliation.

The Wallabies, who lost their second ranking to South Africa behind the All Blacks following their seismic loss, are favourites to win their 11th of 13 home Tests with the Springboks since their last Tri-Nations series success in 2001.

The Springboks have not won in four encounters at the Sydney Olympic stadium.

"We haven't won the Tri-Nations or the Bledisloe Cup [against New Zealand] for a long time, so it's a great opportunity for us to challenge for that again," Wallabies' hooker Stephen Moore said.

"You've got the Mandela [Challenge] Plate, the Bledisloe Cup and the Tri-Nations ... if we really knuckle down in these next four games, we can potentially win those trophies."

Alarm bells will be sounding if the full-strength Wallabies cannot overcome the Springboks, missing key men like Jaque Fourie, Jean de Villiers, Bryan Habana, Fourie du Preez, Juan Smith, Schalk Burger, Victor Matfield, Bakkies Botha, Tendai Mtawarira and Jannie du Plessis.

The Wallabies, who possess one of the most lethal attacking backlines in the world with Quade Cooper, Will Genia, Kurtley Beale and James O'Connor, will be stung to respond after their press shellacking this week.

"I suppose it's not probably the best result for us," Boks' skipper Smit said.

"There's certainly no chance of us catching them unmotivated right now. They'll be pretty motivated to turn things around."

Smit said he expects Australia to target newcomers, props Dean Greyling and Werner Kruger and number eight Ashley Johnson.

"These guys have come through a pretty successful [Super Rugby] campaign. Dean has gotten a chance now because of an injury to Gurthrö Steenkamp and Werner's been going for about three seasons with pretty solid performances," he said.

"They'll be nervous and I'm pretty sure Australia will want to have a crack at them up front."

South Africa, who travel to New Zealand to play the Tri-Nations champion All Blacks in Wellington on July 30, last won the southern hemisphere championship in 2009.

"They won't be undercooked against us. We know that," coach Peter De Villiers said.

"We've all been through those kind of lows in our lives too, that's a learning curve for all of us and what they took from it (Samoa loss) will determine how they're going to come into this game.

"Genia and Cooper are a hell of a danger, there's a lot of dangers in the Wallabies' side."

Deans said it was up to the Wallabies how they reacted to last week's nightmare.

"Last weekend, our standards were inadequate for what is required at Test level and we paid the price for that," Deans said.

"Last Sunday was a massive wake up call for the group.

"We can't turn back the clock on that performance, it will stay with us as a reminder, but we do have total control as to how we respond.

"That is the challenge that we have ahead of us."

AFP