WELLINGTON (AFP) - The All Blacks on Tuesday (Aug 13) warned Australia will face an intense physical battle in the Bledisloe Cup decider but vowed to stay on the right side of the law.

The world champions were keen to place the emphasis on discipline for Saturday's crunch match in Auckland after lock Scott Barrett was handed a three-match suspension for a shoulder charge in last week's shock 47-26 loss to the Wallabies.

"We lost the physical battle and we've got to be better at that (but) that doesn't mean you go out there and just be physical at all costs," assistant coach Ian Foster told reporters.

"The most physical players are the smart ones who know how to accelerate into contact, they're accurate with clean-outs and they do it within the bounds of the law - if you don't then you're going to expose yourself to judgement." The All Blacks have form for going in hard after a defeat, dishing out a brutal beating to Ireland in Dublin in November 2016 to avenge the hosts' historic first-ever victory over New Zealand in Chicago two weeks earlier.

But veteran lock Sam Whitelock said his side could not afford to let intensity slide into ill-discipline.

"We want to play hard, but we've also got to play fair," he said.

"There are a thousand different cameras and different angles, things you probably got away with in the past is something that's not going to happen now." Wallabies backrower Isi Naisarani said the Australians knew their opponents would be hurting and were prepared for the onslaught.

"They're going to come hard at us, they're going to front up and they're going to be physical, so we'll need to match them," he said.

Naisarani was undaunted at the prospect of facing the All Blacks at Eden Park, where Australia have not won since 1986.

"I'm just looking forward to it," said the Fijian-born 24-year-old, who is hoping to help Australia lift the Bledisloe for the first time in 17 years.