The Wallabies believe the intensity and heavy combat of the Tri Nations has them steeled to withstand whatever Ireland can muster in Saturday's high-stakes Rugby World Cup encounter in Auckland.

Despite their unconvincing form, the Irish are talking up their chances of producing a boilover that would likely leave Australia needing to win five consecutive sudden-death matches to lift the Webb Ellis Cup for the third time.

"Australia are a very good team. You'd be foolish to say anything else but there's no point in me sitting here saying I don't think we can beat them," Gordon D'Arcy said before he teams with talismanic skipper Brian O'Driscoll for their record 45th Test together as Ireland's centre pairing.

"You can't put them on a pedestal. We have to look at them like every other team we've ever faced - then just go out and beat them."

The Wallabies respect Ireland, with halfback Will Genia declaring the O'Driscoll-inspired outfit one of the more exciting northern hemisphere teams with an ability to threaten the best sides in the world with their Gallic flair.

"They're a side that can play the traditional northern hemisphere style but also they like to play with the ball as well with guys like Brian O'Driscoll," Genia said.

"They've got a great backline. They'll test us in a lot of areas and the biggest thing for us is focusing on what we do well and try to do that and try to impose that on them in both attack and defence.

"We're lucky that we play sides in the top three in the world, in South Africa and New Zealand, throughout the year coming into a World Cup tournament.

"That obviously stands you in good stead.

"We're even better for the fact that we got to play Italy, who obviously tested us and are a good side.

"All those games prepare us well for this game and it is the pivotal game for us in the pool."

The winners of the Eden Park blockbuster this weekend will almost certainly top Pool C and face either Wales or Samoa in the knockout quarter-finals, while the losers can expect to strike defending champions South Africa.

The Wallabies will be without strike winger Digby Ioane, who on Wednesday declared his surgery to repair his broken right thumb a success.

"It went well. Can't wait to play again," Ioane tweeted.

Without arguably the game's form winger for at least Australia's remaining three pool games, coach Robbie Deans must decide on a replacement who will also need to fill Ioane's defensive duties in the Wallabies midfield to allow playmaker Quade Cooper to drop out of the front line.

"He's a world-class player. He gets you over the advantage line more often than not, so it is a big loss," Genia conceded.

"But we've got quality players like Drewy (Mitchell) and obviously we've got James (O'Connor) to probably come back into the starting line-up as well.

"So we'll obviously wait and see what Robbie wants to do. But whatever decision he makes, I'm sure there's quality players who are going to put their hand up."

Indeed, the ever-dependable Adam Ashley-Cooper has put his hand up to fill the void.

"I'll defend anywhere, like I'll play anywhere," Ashley-Cooper said.

With O'Connor certain to be reinstated on the right wing after his match-turning cameo in Sunday's win over Italy, Deans may choose to move O'Connor to the left wing as a straight swap for Ioane and ease Drew Mitchell back to Test rugby from a dislocated ankle via the bench.

That would least disrupt the Australian backline and enable crash-tackling Anthony Faingaa to remain at outside centre to mark up on O'Driscoll.

Possible Australian team to play Ireland: Kurtley Beale, James O'Connor, Anthony Faingaa, Pat McCabe, Adam Ashley-Cooper, Quade Cooper, Will Genia, Radike Samo, David Pocock, Rocky Elsom, James Horwill (capt), Dan Vickerman, Ben Alexander, Stephen Moore, Sekope Kepu. Res: Tatafu Polota-Nau, James Slipper, Rob Simmons, Ben McCalman, Scott Higginbotham, Luke Burgess, Drew Mitchell.

Brought to you by AAP © 2024 AAP