All Blacks coach Steve Hansen has fired a shot across Australian opposite Ewen McKenzie's bow.



Hansen said today that he believed his Wallabies counterpart was racked with uncertainty over whether to play Quade Cooper or Matt Toomua at first five-eighth.



Asked if he felt mentally challenged by the intense secrecy that has surrounded Australia's line-up for Saturday's Bledisloe Cup match in Sydney, Hansen said: "No. The better question would be is he [McKenzie] feeling a bit mentally challenged because he doesn't know which five-eighth he wants to play?



"He's in a difficult situation, isn't he. I'm imagining when [former coach] Robbie Deans wasn't picking Quade Cooper he was saying, 'I'll pick you, I'll pick you'.



"Now our information is he's going to pick the other bloke [Toomua]. There are only two reasons he wouldn't want to tell them.



"One, he's not sure himself, or two, he doesn't think they can cope with the pressure of being out there in the public too early.



"So it's not affecting us. It doesn't bother me a hoot who they play."



He believed Toomua would be at first-five and that his Brumbies team-mates, Christian Lealiifano and Tevita Kuridrani, would play outside him.



The All Blacks expect the Wallabies to mimic the Brumbies' rushing defensive screen in the backs in a bid to put them under pressure behind the advantage line.



But whatever combination McKenzie picks, Hansen made it clear the Wallabies would be under intense pressure because of the arrival of a new coach.



"I only have to think back myself to when I had my first test match as [All Blacks] coach," he said.



"Whether you want to admit it publicly, there is pressure because there's a question mark.



"Australia hasn't had a great run against us for a wee while now. That's all been attributed to Robbie Deans, which I think is a bit unfair.



"Everyone seems to think Ewen is going to make the difference, so there has to be pressure on him, because what happens if it doesn't work?



"There's a lot of pressure and that's why they will turn up and give it everything they've got. We need to match that intensity or better it."



Hansen said Wellington hooker Dane Coles' omission from the All Blacks squad was not a reflection of his scrummaging ability.



"Dane's problem is he hasn't played. He got injured just after the second test [against France] and hasn't played any rugby. He's done a lot of running," he said.



"The coaching staff, along with the wellbeing group, thought it would be better if he got 40 or 50 minutes tonight [for Wellington], then be available next week. That's the only reason he missed out."



Hansen said it was incorrect to say the selectors believed the new scrum rules being used during the Rugby Championship better suited older hookers Andrew Hore and Keven Mealamu.



"I don't think so. I just think they will reward people who can scrum. Colesy can scrum, so I'm reasonably happy with where he's at," he said.



"We just need to give him some game time and some confidence with his calf."



Hansen indicated Chiefs lock Brodie Retallick would have pushed hard for a starting berth had he not missed last Friday's training match, where the All Blacks got their first chance to trial the new scrum laws.



"That's part of the reason. We have three really good locks. We can only start with two of them," he said.



The Wallabies are expected to name their side today.