The 63-Test halfback, who retired from international rugby in 1993, prefaced his comments by saying he had "cut the umbilical cord" and did not follow the team as avidly as he once did.

But his remarks around the resoluteness and mental fortitude of Michael Cheika's side will no doubt prick the Wallabies' ears ahead of a third Bledisloe Cup clash with the world's No.1 team.

"My reservation is, do they have the belief and the confidence?" Farr-Jones said. "I hear good things coming out of the camp but unless you're in the camp, you don't really know.

"I'm not in the inner sanctum and I haven't been in the inner sanctum for a hell of a long time but I just don't know if the guys have got that mental toughness that you've seen in past teams. It is that thing of 'whatever it takes'.

"Confidence; you can couple that with mental toughness. It's winning in those critical stages when you're defending a five-metre scrum, you're just in front with a couple of minutes to go. You know that you have whatever it takes to defend your line.

"You've got to start winning some of those big matches and get that confidence a year or two in advance [from the World Cup]."

Cheika prides himself on being able to get his players mentally ready for such challenges and no doubt Farr-Jones' comments will cause a stir in the Wallabies camp ahead of an important battle.

Halcyon days: Nick Farr-Jones and coach Bob Dwyer enjoy victory over the All Blacks in Wellington in 1990.

Farr-Jones, a former chairman of the NSW Rugby Union, does believe the Wallabies stand a chance of claiming an underdog victory at Suncorp Stadium but also said: "We could win by five but they could win by 30."

The 55-year-old, who captained his country on 36 occasions, referenced the Australian team of 1990 that went to Wellington and claimed a gritty 21-6 win in tough conditions against the odds.

"When you've played a few Tests against the All Blacks, you have to have a belief and confidence," Farr-Jones said. "For me, it was Wellington 1990 when you get over the line, when you've had a good period against this team and then all of a sudden you form this confidence that you can beat these guys.

"Through the early 1990s and last couple of years in my time in the team, we knew we could beat them on any day.

"It was a bit of a catch-cry of our team that day in Wellington: 'Whatever it damn well takes'. I recall our defence in the [World Cup] semi-final against the All Blacks in Dublin. They didn't score a try against us. It's the mental toughness I'm not sure the guys have that at the moment."

Former Wallabies coach Rod Macqueen was the last man to lead an Australian team to World Cup glory.

He was pressed on Farr-Jones' comments and said it was hard for him to make judgment but passed on his experiences in All Blacks encounters.

"Some of the decisions we've been making on the field indicates we've got to be a bit more positive in the way we go about that," Macqueen said. "We had great respect for the All Blacks and because of that we knew how good we had to be to beat them. We knew they were always going to come back. I see plenty of respect coming from the Wallaby camp."

Asked whether the Wallabies had what it took to win the World Cup in two years' time, Macqueen replied: "It's good to see stability in the side. The more they can get of that and understanding their playing style, the greater chance we've got this far out to make sure we've got a really well-prepared team for the World Cup."