Stirling Mortlock praised Michael Cheika for restoring Australia's belief, crediting the Wallabies coach for the nation's sensational run to the Rugby World Cup final.

Australia will face reigning champions and trans-Tasman rivals New Zealand in Saturday's decider at Twickenham as they bid to become the first country to win three World Cups.

The Wallabies have made it to the final without losing a game, having upstaged tournaments hosts England and Wales in the pool stage, but the future was bleak when Cheika replaced Ewen McKenzie last October.

Cheika took over from McKenzie with Australia on a four-game winless streak, following defeats to New Zealand and Argentina.

However, the 2014 Super Rugby-winning coach has slowly but surely rejuvenated the Aussies, who slipped to sixth in the world rankings in March - their lowest standing since rankings were introduced in 2003, by allowing his players to take the game on.

"He's got very high standards first and foremost. And in particular the intensity and level that he expects the guys to be training at," Mortlock told Omnisport.

"He's also got a great ability to bring the best out of his players, he's a very good man-manager. All the players that have played under Cheik respect him and love to play for him and so as a coach, a leader, that is a fantastic attribute to have as a coach.

"What he has also done is gone back and looked at the history to see when Australia has done really, really well and what was the hallmark and ethos, of culture of those teams. That's what he's brought to the table for this team.

"It's not about having constraints, it's about expressing yourself as a player and a team. That real back yourself mentality is the Australian way, you look at our culture of people and really our performance as sporting teams has always been to back yourselves.

"That's definitely one of the key traits of the current Wallabies outfit, they don't die wondering, they back themselves and it's great to see them do that."

The Wallabies came into the tournament as contenders after winning the Rugby Championship for the first time since 2011.

Australia ended their All Black curse, which spanned 10 Tests up until August, in Sydney, so the nation's exploits at the World Cup come as no surprise to Mortlock.

The 38-year-old, who featured in Australia's heartbreaking 20-17 loss to England in the 2003 final, said: "I've not been surprised, but I've certainly been impressed. There was always the incline and hope that the Wallabies could perform really well in this World Cup and the Rugby Championship form gave a lot of people the thought that could possibly happen. 

"However, being in such a tough pool there was always going to be a fair question over whether that was going to happen.

"The great thing from my perspective is that under Michael Cheika this Wallabies outfit have really developed a fantastic work ethic and culture which underpins how they are doing everything day in, day out and that certainly shines through in the way they have been playing."