Ryan Harris will bowl in the Sydney Cricket Ground nets this morning to prove his fitness to remain part of what Glenn McGrath believes is the best- performed attack of the modern era.
The veteran quick is battling a knee problem but it appears increasingly likely that he and all-rounder Shane Watson (groin) will be fit for the fifth Test as Australia attempt an Ashes clean sweep.
Vice-captain Brad Haddin was bullish about the pair's prospects of remaining part of an unchanged XI and said they needed only to confirm their fitness at the final training session today.
"The only way he won't play is if he's injured and he's not injured at the moment," Haddin said. "I think that dodgy knee of his is feeling good."
The Australian bowlers reversed their normal practice by resting yesterday before bowling today on the eve of the match.
Haddin said the training schedule had to be flexible during back-to-back Test matches and was designed to give the paceman the greatest opportunity to play.
Watson was also likely to be fit, Haddin said, after his handful of overs at the MCG last week suggested that he would be able to bowl at the SCG.
"We would love to have the same group go out that we had at the start of the tour," Haddin said. "If they are right to go they deserve that right to come out in this fifth Test."
As England prepare to hand Test debuts to leg-spinner Scott Borthwick and Irish quick Boyd Rankin in place of Monty Panesar (calf strain) and Tim Bresnan, McGrath lauded Australia's attack as the best he had seen.
McGrath led a nearly unstoppable attack a decade ago but believed the combination of Harris, Mitchell Johnson, Peter Siddle and Nathan Lyon was superior to his 2001 quartet that included Jason Gillespie, Brett Lee and Shane Warne.
"Looking at the way the bowling unit has gone about its business this series - that's probably as good as I have ever seen," McGrath said.
"They have got good bowling plans, they are bowling well, they are executing their plans well and it's working."
McGrath said he had predicted a 5-0 result "since day two at Brisbane" and claimed the prospect of a whitewash was created by England problems that emerged in the previous series.
"England had issues in the Ashes series in the UK," he said.
"Australia were finding their feet with Boof (coach Darren Lehmann) coming in and all the big moments they lost.
"Three-nil was an unrealistic scoreline and I thought England had a lot of issues then.
"They have come out this series."
Borthwick, who had a strong season for Durham with the bat, was brought into the England camp last week after playing club cricket in Sydney this summer.
Australia should know about him, with Haddin playing club cricket with him, Chris Rogers playing several county matches against him and batting coach Michael Di Venuto spending four seasons with him at Durham.