Australia coach Michael Cheika has told England that :talk is cheap", saying his Wallabies pack will prove their hosts wrong at Twickenham on Saturday.

Cheika is confident his forwards will be up to the task in the pivotal Pool A clash despite the claim from England No.8 Ben Morgan that Cheika's side will be "concerned" by the hosts' scrum performance against Wales.

But tensions are clearly rising. Speaking after announcing his team on Thursday, Cheika said he would let his players do the talking that counts for Australia.

"It's not that we're not ready," Cheika said when asked if his pack was a weakness. "I know they think we're weak in the forwards. It's pretty obvious. They're saying it out loud and they've done it to us; stuck it to us.

"There's nothing we can say that's going to make any difference; [the] only place that's going to make it different is on the field on Saturday night. Show our colours -- talk's cheap."

There is little doubt the Wallabies forwards have improved under Cheika, particularly their scrum and maul. The two-time world champions have already scored four tries from lineout drives this tournament, and former Argentina prop Mario Ledesma has made great strides with the scrum. But Cheika said he wanted his side to play a balanced game, something they'd been working on right back to the early weeks of Super Rugby.

"That stuff [talk], it's not even resonating in my mind," he said.

"I'm thinking about my lads, how we're going to play, the best balance between good technique, good tactics and the stuff you don't need talent for - which is very big physicality.

"[We're] trying to get that balance right because if you go one direction too far in any of those things you end up paying the penalty. Anything in life is about balance and then we want our forwards to combine with our backs as well. We're looking very team focused.

"Something we've worked very hard on is to build our team spirit, our team connection over all of Super Rugby, belief in ourselves, and [to] be ready for whatever challenge is put in front of us.

"The only way that people who think like that [like Morgan] can change their mind is if we give them reason to change."

Pre-match verbal exchanges have also seen former Wallabies coach Bob Dwyer weighing into the scrum debate.

The 1991 World Cup-winning coach took aim at England prop Joe Marler and his "illegal" angling in. There has also been a social media campaign running in Australia, sparked by ESPN correspondent Brett McKay, under the #ScrumStraightJoe hashtag.

Lancaster responded to Dwyer's comments on Thurday, saying the England scrum was "good and honest and excellent", but Cheika was steering clear.

"The only scrummaging technique we're worried about is our own and that's all we're going to talk about," Cheika said. "Bob's got massive experience, he's very well respected, won a World Cup; his opinions are always out there.

"But for us, trying to pick a fault in your opponent whether it's [the] scrum or something else, and complain is a weakness on our part.

"We don't want to be weak mentally; not look for any excuses and be responsible for whatever actions we put out on the field. What we can manage is our technique and the way we scrum."