The first verbal barbs were fired from across the ditch in the build-up to the Wallabies' final against the All Blacks, with Folau described as a "borderline liability" in a newspaper column.

It's a significant sledge against one of Australian rugby's most prized possessions, who boasts a strike-rate of 18 tries in his 37 Tests.

But he has scored just once in the past 11 matches for the Wallabies and opponents are working out ways to take him out of the contest by nullifying his strengths.

Australia's fullback has been struggling to cope with an ankle injury and is still trying to break through for his first World Cup try.

He made just 55 metres in his 64 minutes on the field, making one break and beating two defenders in the Wallabies' semi-final win against Argentina last weekend.

Is Cheika worried that Folau seems below his best? "I never doubt that bloke. Never. If they write [Folau's a borderline liability], put it in a headline," Cheika said.

Is Folau in top form? "I think before he got his injury he was in good form, he was carrying the ball really well," Cheika said.

"The injury bothered him a bit, he missed a game and then he played [against Argentina] with that injury but on the improve.

"He felt good enough to be able to do his job and I think he's only going to get better after that … The proof of the pudding will be in the eating on Saturday."

Folau recovered from his ankle problem to take his spot at fullback in the 29-15 win against Argentina in the semi-final before he was replaced by Kurtley Beale in the second half.

Beale has been one of the Wallabies' best players from the bench in the tournament so far, but there's no chance Folau will be dropped to the bench for the biggest game of his rugby career.

The Wallabies got good news the morning after their win against Argentina with David Pocock (calf) getting through 80 minutes unscathed.

Matt Giteau is nursing a niggling groin problem, but it is not expected to keep him out of the final while prop Scott Sio is a chance of making his return to the front row against the All Blacks.

Scott Fardy got a knock on his hip while Pocock copped a whack to the nose that left blood streaming down his face for almost the entire match.

"[But] everyone's up and about. I think we realise it's a short week and we've got to get going and the boys are all ripping into their recovery," said captain Stephen Moore.

"It's going to be important to recover well so we can still train hard through the week."

The Wallabies have beaten the All Blacks just once in the past 12 Tests between the rivals.

Folau has just one win against New Zealand in his eight attempts since switching from AFL to rugby union.

But with NRL grand finals, State of Origin battles and a Super Rugby title to his name, does Cheika start to question him on the eve of a World Cup final?

"Never."