Australia scrum-half Nic White says there is "definitely more to come" from the backs in their World Cup quarter-final against England.

The unpredictable Australian forwards have been winning the plaudits so far, but White says the backline is a "force to be reckoned with".

The Wallabies finished second in Pool D after defeat by Wales and unconvincing wins over Fiji, Uruguay and Georgia.

"As a team and a backline, we are confident we are doing well", he said.

In the final pool match against Georgia, a side renowned for a strong pack, the Wallabies forwards dominated the collisions, the breakdown and set-piece, only for the backs to suffer cohesion issues.

Part of the reason could be that head coach Michael Cheika has picked three different halfback combinations in the four Pool D games, with fly-half Christian Lealiifano saying he does not know if the rotation is a "strength".

"We're trying to focus on getting our best combinations that we feel will put our best game out there," Lealiifano said.

"There's a few different combinations in there."

However, Cheika's preferred partnership in midfield has been Samu Kerevi inside James O'Connor, and the former has beat more defenders (20) than any other centre in the tournament so far.

Kerevi's potency will be a real threat for the Wallabies and the 26-year-old has successfully taken on more defenders than England's top two exponents in the centres combined (Manu Tuilagi 9, Jonathan Joseph 8).