With the prospect of captain Pat Cummins being fit for the Ashes receding by the day, Australia's hopes of retaining the urn may rest on managing one of the biggest shake-ups to their leadership and bowling against England in years.
A back stress injury has cast doubt on Cummins participating in the series starting on November 21 in Perth, with the paceman yet to resume bowling in his rehabilitation period.
Losing Cummins for Perth alone would require a major shift in the Australian mindset, given the 32-year-old has been ever-present since making his Ashes debut in 2017/18.
Cummins has played every series-opener and across four Ashes campaigns missed only one match, when ruled out of the 2021 Adelaide test for eating at the same restaurant as a person who tested positive for COVID-19.
That durability has seen him claim 91 English wickets at an average of 24.10, leading his regular pace colleagues Josh Hazlewood and Mitchell Starc.
With Cummins fit and firing, Australia have never lost the urn since reclaiming it in 2017.
Little wonder that the prospect of Cummins being absent from the upcoming series has raised English hopes.
"Should he be missing in Perth, it would unquestionably be bad for the series and bad for Australia, but give a huge lift to an England team looking to win their first test - never mind series - in the country for more than a decade," former England captain Michael Atherton wrote in The Times.
While Scott Boland is likely to be first in line to replace Cummins in the pace bowling unit, Cummins' absence will put the spotlight on how 35-year-old Starc and 34-year-old Hazlewood are managed throughout the five-test series.
Starc slogged through five tests against India in the last home summer but Hazlewood has not managed a full Ashes series since 2017/18 due to injuries.
Fast-bowling all-rounder Cameron Green will be under pressure to ease the workload of the front-line quicks but may also need to be managed carefully as he works his way back into bowling after spinal surgery.
Vice-captain Steve Smith is in line to take the captaincy if Cummins is unfit, having stepped in for the regular skipper during the two-test series against Sri Lanka.
Though Smith was a full-time captain prior to the Newlands ball-tampering scandal in 2018, it will be another paradigm shift for a team that has grown accustomed to Cummins' calm leadership during their rise to the summit of test cricket.
Cummins said last week his latest scan on his back showed the injury was lingering and he would need to be careful.
Cricket Australia said no decisions have been made on his availability for the Ashes.
Starc on Thursday said he was unaware of the latest news on the injury but said Cummins would be able to get back up to speed quickly once cleared to resume bowling.
"I found one thing playing with Pat and being close with Pat, he doesn't need much (time)," he said.
"He just knows when to switch on or how to switch on really quickly."
