The desperate Wallabies aim to celebrate coach Robbie Deans' 50th birthday in style with a cherished Tri-Nations victory, and plenty of tries to ice the cake.

Former All Black Deans notches his milestone on Friday but the result of Saturday night's clash with South Africa will determine whether it's a happy occasion or not.

A huge cricket and squash fan, the modest Deans isn't about to wave his bat at bringing up his half-century, knocking back interview requests about the milestone.

His players were unaware of the significant anniversary on Thursday, with inside centre Berrick Barnes astounded at his age given his fitness and a distinct lack of grey hairs.

"Half-century! Gee, he looks good doesn't he!," said Barnes.

"His knees certainly aren't 50, they're older than that, but other than that he's calm under pressure.

"He's given us all the necessary tools we need. We just have to take it all on to turn the tide."

Now Australia is out of Tri-Nations reckoning following four straight losses, Barnes - a field-goal expert - talked up the Wallabies' desire to play running rugby to end their worst streak since 2005.

"We've got nothing to lose,' he said. "I reckon we need to play some footy as well so we'll be backing ourselves."

Hailed as Australian rugby's messiah last year, Deans' 50th comes at a time the code is under pressure due to poor results and a lack of entertainment compared to rugby league and AFL.

Straight-talking Barnes played down the negativity.

"Who knows? A couple of papers own league so they're going to pump it up," he said.

"We're copping a bit of stick and it's hard down here because we've got to compete with four other codes and unfortunately there's not many tries being scored.

"We'll be doing our best to put on a spectacle but you've got to have results too. So we'll be doing everything we can."

Brought to you by AAP © 2024 AAP