Captain Alastair Cook says his 100th Test will be the "toughest" of his career as England look to turn around the Ashes after two heavy defeats.
Australia will regain the Ashes if they win the third Test, which starts in Perth on Friday at 02:30 GMT.
The tourists, who have won the last three Ashes series, have won just once - in 1978 - in 12 Tests at the ground.
When asked whether his 100th Test would be the toughest of his career, Cook said: "I think it's a fair point."
He added: "After what's happened so far, I'd say so. Your next challenge is always the toughest."
The only side in Ashes history to come back from 2-0 down to win was the Australian side led by Don Bradman in 1936-37.
It will be a tall order for England to achieve the feat, after the 218-run defeat in Adelaide followed a 381-run loss in the opener in Brisbane.
They have only passed 200 runs once in four innings so far. Worse still, England have failed to reach 400 runs in any of their innings in seven tests against Australia this year.
However, Cook added: "Our confidence has taken a hit after the first two matches but the squad has made a real conscious effort. We have to look forward, rather than look back.
"I don't think it's been about lifting the players. That hunger and desire has always been there in this side. We have got another opportunity to show it this week."
The tourists have struggled against the short ball and, in particular, the bowling of left-arm paceman Mitchell Johnson, who has taken 17 wickets in the two opening Tests.
Cook said: "It's down to individuals. I think our shot selection against him [Johnson] at certain times has been quite poor in this series and I think that's why he has had a lot of success against us."
England coach Andy Flower has said he will make changes to the team, with seamer Tim Bresnan expected to return from injury, while Gary Ballance, Jonny Bairstow, Steven Finn and Boyd Rankin could also come into contention.
Australian captain Michael Clarke, who will also play in his 100th Test in Perth, was confident fast bowler Ryan Harris would overcome a sore knee to play, but will wait until after the toss to name the team.
"We don't know the team at this stage now," he said. "We're going to wait for the toss. We'll see how everyone pulls up after training and it'll give us another opportunity to look at the wicket as well."
However, all-rounder James Faulkner has been ruled out of the third Ashes Test with a fractured thumb.
The heat will be a factor, with temperatures expected to hit 36-38C during Friday-Monday.
Clarke added: "It's going to be hot and they're going to be long days, but I think both teams will find it quite hot."
Ahead of his 100th Test Cook said: "It's a huge honour for me to join the 100 club, one I never thought I'd get to when I started playing.
"It is a special day, and it would make it even more special if we can produce a performance we are capable off."
Clarke added: "In regards to being your 100th Test, its not a focus at all. It's fantastic that I have been able to play 99 Tests for my country and it's something that I'm proud of.
"But it's about having the a chance to win the Ashes and continue to perform like we have in first two Tests."
