Cardiff: Australian coach Tim Sheens won't settle on his best 17 until after the pool stages despite naming a full strength side to play England on Sunday morning.
Sheens said the seven players not picked in the opening game will feature in Australia's second pool game against Fiji before mixing that side again ahead of their final group game against Ireland.
That means Boyd Cordner and Josh Papalii will make their Test debuts next week while the likes of Jarryd Hayne, Josh Morris, Daly Cherry-Evans, Michael Jennings and Nate Myles will also have an opportunity to play their first game on tour.
As England look to implode, the veteran mentor wouldn't be drawn into the dramas plaguing the English side less than 24 hours before the two teams clash.
"An embarrassed side is a dangerous side," Sheens said. "When things go wrong they can have the exact reverse effect. We need to make sure our game is right.
"We have a respect for this team."
With both teams expected to cruise through their remaining pool games an opening win is crucial. The loser would almost certainly face New Zealand in the semi finals.
"Winning tomorrow doesn't guarantee you the final and losing doesn't mean you won't make it," Sheens added. "It's not a win-at-all-costs game but it's an important game.
"You've still got two more games in the pool. If you rise to the occasion and drop off after that, you can find yourself ambushed in another pool game.
Australia haven't played together since their mid-season Test victory against New Zealand after the Kangaroos opted against playing any warm-up games. England probably wish they had followed the Australian's lead following their poor showing to Italy – losing 15-14.
Sheens said Cronulla prop Andrew Fifita was controlling his nerves ahead of his Test debut from the interchange bench.
"The big games he played in Origin has helped [settle him]," Sheen said. "I've said to him it's that type of performance and atmosphere. He has contained himself pretty well."
Australia had a final training run at Millennium Stadium on Saturday ahead of their opening game against England on Sunday morning.