Talismatic Paul O'Connell returns to the starting lineup for Ireland for the first time in 18 month but has warned his team mates that the Wallabies are a growing force.
The 34-year-old Munster legend is delighted to be back in the fold for Ireland but is expecting a baptism of fire against the Aussies.
"They are certainly a better team and they have a different philosophy," he said.
"(Quade)Cooper has been brought back in and has been given the opportunity to play the way he wants to play.
"Australia are coming off a really tough Rugby Championship and when you have tough championship like that you tend to find out a lot more about yourself and you tend to get better."
Australia boss Ewen McKenzie has brought lock Rob Simmons, blindside flanker Scott Fardy and prop Sekope Kepu and feels that the game will be won and lost at the breakdown.
"The breakdown in every game is the crucial area, if you can get quick ball with the back-line we have, I think you can do damage and they're the same.
"We really need to defend well against them and the breakdown plays a massive role."
Most analysts are predicting that Ireland will have supremacy at scrum-time but O'Connell, who came off the bench to good effect in teh 40-9 win over Samoa last week, doesn't feel it will be as straight-forward as that.
"I think it's going to be really tough in the scrum , I don't think it's going to be anything like the third test against the Lions," he added.
After an extended period in the international wilderness, O'Connell is relishing being back in the mix with Ireland, especially with Joe Schmidt at the helm.
"It's been a frustrating couple of years. I was a long time away from the Irish setup but it's great to be back but it's been a really enjoyable time, the way we've trained and the way we prepared," he said.
"The squad has changed dramatically since the last time I was involved 18 months ago in terms of the depth of the squad.
"There is a lot if depth in leadership in the squad with provincial captains and former Irish captains in the squad.
"Any time you can have more leadership on the field is so important particularly against these Southern Hemisphere teams."
Paul O'Connell will be partnered in the second row tomorrow by Devin Toner and Sean Cronin believes the pair could form a formidable partnership.
Former Connacht front-rower Cronin explained: "Dev has been a rock in the Leinster pack this year and he has stepped up to the plate the last 18 months.
"It is fantastic for him, a huge opportunity.
"I thought he did well last week and it is great that he is getting another opportunity and Paulie is coming in next to him.
"I'm sure they can get a good relationship going."
Cronin takes a seat on the bench for Saturday's second autumn clash, with Ulster's Rory Best once again commanding the number two shirt.
Ireland bulldozed Samoa with a brutally-accurate driving maul try for Peter O'Mahony last weekend.
But Cronin knows Ewen McKenzie's Australia will not be so easy to dominate in the tight exchanges.
Backing Schmidt's men to keep their aerial set-piece work simple and tidy, Cronin said the new coach's high-pressure approach is already paying training dividends.
"I thought the lads did fantastic with the drive last week and really got us into the game," he said.
"I think we were probably struggling a bit in the first half, trying to make inroads into the Samoan defence, so it was a good way of getting into the game.
"It was great to maul them over, (forwards coach) John Plumtree was delighted with it., so we are hoping for another one this weekend.
"When you break the line-out down to the throw, the lift and the jump, if you can all three aspects of that correct and everyone goes about their job efficiently, then we believe we have the capability to cause teams problems there.
"If everyone does their job then we have an opportunity to squeeze teams. Intensity is Joe's middle name really.
"He demands what he does from his players and training is no different.
"He is trying to bring that in, game speed, game decisions, that have to be made with the snap of a finger.
"So the sessions have been fairly intense but they've been enjoyable - short and sharp.
"It is great to see Joe (Schmidt) so up for it, he knows how to get his players going and he has the lads well primed for the weekend."