The greenhorn, depleted Wallabies have been urged to handle Argentine hostility "like men, not boys" to snare a momentous Test victory this weekend.

Missing more than half of their strongest starting 15, Australia will field one of it's most inexperienced teams of the professional era against a Pumas outfit eying an historic first Rugby Championship win.

The promotion of backs Nick Cummins and Ben Tapuai for their run-on debuts puts them among a group of seven starting players who boast less than seven Tests experience.

But grizzled skipper Nathan Sharpe has laid down the law to his young, under-strength outfit - stand up and thrive in the extreme noise and pressure at the 41,000-capacity Estadio Gigante de Arroyito.

"Sharpey said 'get your head around what you're walking into - you have to be men, not boys. It's going to be a hostile environment'," said promoted prop James Slipper.

"It's going to be tough. We know that. We're not going to be walking into this game with our heads up. It will be head down and working hard this week."

Sunday morning's clash may be a tournament dead rubber but it's certainly full of importance for both sides, and especially besieged Wallabies coach Robbie Deans.

A backs-to-the-wall win will see Australia end the tournament with a palatable 3-3 record and ensure Deans stays in his job.

Tapuai, preferred at outside centre ahead of Reds teammate Anthony Faingaa, said a victory would be one worth celebrating following heavy criticism of their Rugby Championship form.

"If we win it would be even sweeter," the 23-year-old said. "To prove everyone wrong, all the doubters who have been putting us down."

After being bashed at the breakdown by the Springboks in their 31-8 loss in Pretoria, Deans has increased the strength and size his team in making five changes.

Slipper has replaced Benn Robinson, 122kg powerhouse Sitaleki Timani will play in the back-row, and Cummins and Mike Harris joins Tapuai in a near second-string backline following injuries to Berrick Barnes and Adam Ashley-Cooper.

It leaves the Wallabies backline - missing regulars Will Genia, Quade Cooper, James O'Connor, Drew Mitchell, Barnes and Ashley-Cooper - with a combined total of just 88 caps in experience.

Highlighting the new combination's inexperience, 60 of which are held by five-eighth Kurtley Beale (30) and winger Digby Ioane (30), who has overcome a knee problem.

In stark contrast to the Wallabies disruptions, the Pumas have the luxury of fielding the same team for the third match in succession.

Local pundits predict Argentina will again go against their normal instincts and play an expansive game as they did in the 54-15 loss to New Zealand.

But Deans fully expects the home side to unleash their traditionally brutality up front, where the collisions will be huge.

"They will look to take us on physically as a pack," he said. "They will want to maul us and our selections are reflective of what we expect from them."