Twelve days.

That is all it took Australia to retain the Ashes as England folded in an all-too familiar capitulation Down Under.

England required a miracle to keep the series alive going into the third Test at the MCG, but the tourists were powerless to prevent Australia from sweeping to yet another victory and taking a 3-0 lead to retain the Ashes.

While England’s hopes of regaining the urn have been laid to rest, two crucial Tests remain as they look to avoid a humiliating 5-0 series whitewash.

On the eve of the fourth instalment of this five-part drama, we examine the key talking points and team news as both teams head to Sydney for the penultimate Test of what has so far been a one-sided affair.

Root and branch review

When Joe Root leads England out in Sydney on Tuesday evening he will become the longest-serving Test skipper in the country’s history, overtaking predecessor Sir Alastair Cook’s previous record of 59 matches.

But any sense of pride in that achievement will be tempered by the fact that he overseen an unsuccessful Ashes campaign for the third time in his tenure.

After a 4-0 defeat in 2017/18 and a 2-2 draw at home in 2019, Root and his side are 3-0 down and face the unenviable prospect of an humiliating whitewash.

England’s dire return Down Under has led to questions over Root’s long-term future as captain, with Ben Stokes mooted as a potential successor.

The all-rounder has captained England once before and is regarded as the only realistic candidate to take over, but Stokes has been keen to distance himself from the role having only just returned from an extended break for mental health reasons.

“I've never really had an ambition to be captain”
- Ben Stokes

“I’ve never really had an ambition to be a captain,” he said, addressing the speculation.

“Captaincy is more than setting fields, picking the team, making decisions out there in the middle. A captain is someone you want to go out and play for. Joe Root is someone I always want to play for."

Having wrung the changes for the do-or-die third Test in Melbourne, England are likely to stick with the same side that capitulated at the MCG.

Indeed, the most high-profile casualty from the defeat in Melbourne will be head coach Chris Silverwood.

The under-fire England supremo was due to miss the fourth Test after a member of his family returned a positive test and the 48-year-old has since contracted Covid-19 himself.

England's backroom team has been stretched to breaking point in Sydney by the enforced absences of Silverwood, Jon Lewis, Jeetan Patel and Darren Veness – all of whom are isolating with the virus.

Other support staff have been drafted in to support training drills, including those from the communications and medical teams, while players have been offering each other tips, advice and throwdowns in a bid to maximise the sessions.

Keen to put a positive spin on the latest setback in a tumultuous tour, Root said he hoped the side could thrive in the face of hardship.

“With the amount of coaches we have had missing, it has made things disjointed and challenging but it is a chance to come together,” he said.

“You have to stand up and fill those voids where they are. It does not come just from me. Every single player has to muck in to give everyone the best chance to train as well as they can."

Root added: “Training looked very different yesterday and today but it is an opportunity for us to help each other out, get tight and stand up in a bit of adversity.

“Sometimes when you look around the dressing room and see someone who has helped you out, it can galvanise you as a team.

“That is what we need now: stick tight, stay together. It would be easy to get fractious and point fingers at who could be better but we are in this together. As a team we have not performed as well as we can do. We have to stand up, and take our chances here.”

Broad appeal

England bowler Stuart Broad has been recalled by England, replacing the injured Ollie Robinson in the only change to the XI from the third Test defeat.

Earlier this week, Broad described his tour so far as "very disappointing" having only played in one of the first three Tests.

The seamer was the world's leading Test wicket-taker in 2020 but took just 12 in 2021, having played in only seven Tests last year due to a combination of rest and rotation.

The 35-year-old was surprisingly overlooked for the series opener at The Gabba and again in the Boxing Day Test in Melbourne, getting his only chance so far on a flat deck in the day-nighter at Adelaide.

Broad's sporadic absence from proceedings has been the subject of some debate since the first Test.

David Warner, whom Broad dismissed seven times in the 2019 Ashes series, said that it was "a great result that he's not playing" and the decision to leave the Nottinghamshire bowler out of the first Test came in for criticism from Alastair Cook, who said selecting him should have been a "no-brainer".

Broad wrote in his column for the Daily Mail: "As a wobble-seam bowler, I feel as though I missed out on two of the best wobble-seam pitches in Australia. Only playing once has made this a very disappointing trip, one that has not met my personal expectations.

"The biggest frustration is losing the Ashes, being 3-0 down and feeling like I've not really done anything. Not being able, as an experienced player, to influence a series while it's live is tough.

"Has it affected my hunger to play Test cricket? No. Looking at things pragmatically, I would argue that I won't get a better chance to take wickets than at Brisbane and Melbourne. But I must be ready for my next opportunity, whether that be in Sydney, Hobart or beyond.

"There is a long time between now and the tour of the Caribbean in March and I have never been one to make emotional decisions. So I'm not going to make any spur-of-the-moment calls on my future.

"I feel fit, I've come back from the calf injury feeling strong and I'm taking wickets in the nets. That's all I can do given the lack of tour games and the tight schedule."

Aussies eye whitewash

From an Australian perspective, the hosts will be without their leading run-scorer in the series, Travis Head, after the middle-order batter tested positive for Covid-19.

Head, who scored his maiden Ashes century in the first Test at The Gabba, will now remain in Melbourne and isolate for seven days.

Usman Khawaja is the man most likely to benefit from Head’s misfortune having performed 12th man duties for the last three matches.

The 35-year-old is expected to make his first Ashes appearance since the famous Headingley Test of 2019, when Stokes scored an unbeaten century to snatch victory from the jaws of defeat for England.

England's last victory at the SCG

“It’s one of those things where even if I do play, it’ll only be for one game, I understand that situation,” said Khawaja.

“Hopefully I can go out there and score a hundred and do well for the team in the absence of ‘Heady’. I’m just putting my head down, making sure I’m working really hard and doing the best I can for Australia whenever I get the opportunity.”

Elsewhere, Australia's Boxing Day Test hero Scott Boland has retained his place after taking 6-7 as the hosts wrapped up victory in Melbourne on his home ground.

The Victorian retained his spot after fellow pacemen Josh Hazlewood and Jhye Richardson both failed to recover from injuries.

Glenn McGrath's Pink Test

Cricket Australia will once again join forces with the McGrath Foundation for the annual Pink Test in Sydney, taking place this year during the fourth Test of the 2021/22 Ashes series.

Across each day of the Test, players will wear special pink-embossed whites and on day three of the test, known as Jane McGrath day, fans at the SCG are encouraged to wear pink to show their support for the cause.

Aussie bowling legend and BT Sport contributor Glenn McGrath set up the foundation back in 2008 after the tragic loss of wife Jane to breast cancer.

Over the past 13 years, the charity has supported more than 95,000 families, raising vital resources to help fund 171 breast care nurses across Australia.

To donate, or find out more about the McGrath Foundation, click here:

Watch all the action from 10.30pm on Tuesday 4 January as the fourth Test gets underway exclusively live on BT Sport 1HD.