Ireland defence coach Les Kiss says countering Australian half-backs Will Genia and Quade Cooper will be crucial in Saturday's World Cup game.
"They're critical to what Australia do," insisted Kiss.
"There's a lot of talk about Cooper but he relies on what Genia can do to the defence around the ruck area.
"We've focused on closing down the options Genia has. We've got to concentrate on picking the right moment to put pressure on him."
Kiss added:"If the right pressure is there, he has to ask the question of himself whether he's up for it.
"People respond to pressure in different ways and in big Tests that's what it's about."
Kiss expects Australia to continue with the policy of removing Cooper from the defensive line in the Eden Park contest.
The 23-year-old's frailty in the tackle, combined with his threat as a counter-attacker, means either wing James O'Connor or Adam Ashley-Cooper is likely to step into the fly-half channel with Cooper dropping back.
"I'd say James O'Connor has done it before and will go in that channel.
"We feel like they'll stick with that and will put Quade out the back again, keeping him fresh for the moments he's been waiting for to impose himself.
"Is it hiding him or is it being smart? I don't know, it seems to have brought them some value."
Australia are 1/5 favourites to win a match that looked like being Pool C's pivotal encounter when the World Cup draw was made in 2008.
But Ireland's recent form - they lost all four warm-up internationals and looked unconvincing in their 22-10 victory over the USA last weekend - points to the final group game against Italy on 2 October as being the crunch encounter as regards qualification.
Kiss, however, insists the squad are convinced they can cause an upset in Auckland.
"It's nothing like a big game like this to focus the mind but the boys have prepared well," said the Australian.
"I know a lot of people don't give us much of a chance but it's a game the lads are up for.
"The most important thing is what we believe. That doesn't disregard what other people's views are but it's critical for us that we know what we're about and that we believe."