Folau (ankle) and Pocock (calf) are the two biggest concerns facing the Wallabies this week following their heroic defensive effort in a 15-6 win against Wales last weekend.

Fullback Folau is expected to recover in time for the clash against Scotland, even if he is on minimal training duties this week to lighten the workload on his ankle problem.

Pocock's challenge is bigger as Wallabies medical staff try to determine how bad his calf problem is. It's understood the Wallabies are confident Pocock has not torn any muscles.

But the pain was enough to force the hard-nosed flanker off the field in the second half against Wales.

The Wallabies have fallen on the perceived weaker side of the finals draw, with a quarter final against Scotland. If they get through that, they will play either Ireland or Argentina.

But still burnt by losing two of their last three games against Scotland, the Wallabies defence coach Nathan Grey says they won't hold anything back on Sunday (Monday morning AEDT).

"I think it's been pretty clear that we go full-on every game we play. If you get the opportunity to wear that gold jersey, you take it and cherish it," Grey said.

"When the [game-day squad] is selected, we'll be picking every gun we've got. We know at this stage of the competition it's do or die."

The Wallabies will put faith in squad depth to see them through if either fails fitness tests later in the week.

Inside centre Matt Giteau also appeared to aggravate his rib injury, but is expected to be ready to play against Scotland.

Winger Rob Horne is also still with the squad after injuring his shoulder against England and hopes to train this week to prove he can still be a part of the campaign.

Michael Hooper will be back after serving a one-match suspension, while Kurtley Beale has been in superb form and will capably fill Folau's shoes if needed.

In the past, the absence of two of Australia's biggest weapons – Folau and Pocock – would be a killer blow for the Wallabies' hopes of winning the World Cup.

"[But] I think those guys came off and our finishers who came on really solidified the performance and all those guys in difficult circumstances were outstanding," Grey said.

"It showed that to be consistent in this tournament, you've got to rely on your 30-man squad. That's going to be evident moving through into the knockout stages.

"All teams go through injuries throughout the tournament and you have to rely on your whole squad. We've got a lot of confidence in the whole group … they go about delivering. It's simple from that perspective

"When you put on that gold jersey it means a lot. And the expectation is you'll be giving everything you can give."

Beating Wales means the Wallabies avoid South Africa and New Zealand until a potential meeting in the final.

The try-less win will go down as one of the gutsiest performances in Wallabies history, as they repelled a seven-minute siege with just 13 players on the field.

Ireland bet France in the last pool match, meaning they will also avoid the South African and New Zealand side of the draw.

The defending champion All Blacks face a tough test against France in their quarter-final on the weekend.

Winger Drew Mitchell said being able to hold out Wales would boost the squad's self-belief.

"It's one thing speaking about it but we've been put in those situations in training and games, you need belief to get yourself out of those situations," Mitchell said.

"You gain belief as you go through but you also need to go into games with a great deal of belief."

"I think that's something he's (Cheika) very good at is instilling that belief in the squad and also within individuals to play his game and express yourself the way you do.

"We've been working very hard for a long time in our lead up and our campaign for those types of scenarios.

"We knew it was going to be tough and there was going to be pain out there tonight and when we were in those situations we almost bound together even stronger and worked even harder for each other.

"That's something with Cheika and the coaching staff that he's trying to instil in us but also something we would hope our spectators and supporters can see and engage with and buy into.

"We hope they see that, how much we're working for it and how much it means to us."

WORLD CUP QUARTER FINALS

Quarter final one: South Africa v Wales at Twickenham, 2am Sunday AEDT.

Quarter final two: New Zealand v France at Cardiff, 6am Sunday AEDT.

Quarter final three: Ireland v Argentina at Cardiff, 11pm Sunday AEDT.

Quarter final four: Australia v Scotland at Twickenham, 2am Monday AEDT.