Assistant coach Wayne Smith says New Zealand remain wary of Quade Cooper despite his erratic display against South Africa.
The Australia fly-half made several errors in their 11-9 World Cup quarter-final victory.
"He is mercurial, he is dangerous," Smith said of New Zealand-born Cooper ahead of Sunday's second semi-final.
"If he has a real good day you're in trouble, so we've got a lot of respect for him."
Cooper has been a target for local media during the World Cup, being nominated "public enemy number one" by one newspaper in the build-up to the tournament, after a couple of on-field incidents with All Blacks captain Richie McCaw during the Tri-Nations.
"People probably say the same thing about any player who has a bad trot," added Smith of the criticism that has followed Cooper's display.
"We had an experience with Zac Guildford (All Blacks wing) for example, who had a poor game before the World Cup, got a chance in the World Cup and then had a blinder. Quality players come right pretty quickly."
The All Blacks have seen full-back Mils Muliaina and Dan Carter's deputy Colin Slade join the celebrated fly-half in being invalided out of the tournament.
But wing Richard Kahui is fit and available again for Sunday's semi-final after recovering from a hamstring injury which kept him out of the hosts' final pool win over Canada and the quarter-final victory against the Pumas.
"It's not who you've got in the team, it's what you've got inside you that counts at this point and that's what'll win it," Smith added of the challenge now facing the All Blacks.
"We've played each other often over the last few years. We know them well, they know us well. We know it's going to be a massive encounter."
Australia are sweating over the fitness of full-back Kurtley Beale, who is rated as "touch and go" after he suffered a hamstring strain in the dying minutes of their quarter-final victory.
"He'll be a massive loss for us because Kurtley provides so much to the team, not only in attack but just in the mood and excitement of the group," said Wallabies centre Adam Ashley-Cooper. "We certainly have our fingers crossed for Kurtley."
Scrum-half Will Genia is "100% confident" though that even if they have to do without Beale, the Wallabies can repeat their decisive Tri-Nations victory over New Zealand on Sunday.
"I don't know if I could be more confident," Genia said. "I don't want to sound arrogant, I'm not that sort of bloke. I really believe in the guys that we have in this group that we can do it.
"We've got to put ourselves in a position where we can play rather than looking to defend for the whole game.
"We want to play to our strengths, which is obviously our attacking style of running rugby. We need to give ourselves that opportunity."