SYDNEY - Before this series began, the odds of a 5-0 win to Australia were about the same as of Bangladesh winning next year’s World Cup. But Michael Clarke’s men enter the Sydney Test on the verge of completing a clean sweep. England came to Australia with the Ashes in their possession and a sense of stability around their squad. Whatever happens over the next five days, they will leave these shores without the urn and without any real idea of how to fix their problems.

Graeme Swann has retired mid-tour, the vice-captain Matt Prior has been dropped, Jonathan Trott has spent most of the series at home, their only centurion has been the new boy Ben Stokes, they don’t have a batsman in the top five series run scorers, they have only one bowler averaging under 30. They’re a rabble, and even if they avoid a 5-0 defeat this result should hurt more than the 2006-07 clean sweep, for that was against champions like Shane Warne, Glenn McGrath and Adam Gilchrist.

This Australian outfit has been cobbled together after a period of retirements, experiments and abandonments. In recent years, Australia’s Test team has been changed as often as a baby’s nappy and sometimes produced similar results. That was certainly the case in India in February-March, when they were humiliated 4-0 on the field and embarrassed off it. Their success in this Ashes campaign is all the sweeter for it. It remains possible that Australia may take the same XI into all five Tests in the series, which would be a first.

Not every question has been answered for the Australians, who have a three-Test tour of South Africa in a month’s time. Most notably, the No.6 position occupied in this series by George Bailey could be up for grabs after this series. If Bailey plays at the SCG and fails, he can hardly be retained. Whatever happens, though, this squad has achieved everything that was asked of it. Australia have the Ashes and will get their hands on the (replica) urn after this Sydney Test. It’s now just a question of 5-0, 4-0 or 4-1.

Before the Ashes began, Michael Clarke predicted that Mitchell Johnson could be the Player of the Series, so well was he bowling. Brad Haddin has a strong claim to the award but it will take something remarkable for Johnson not to win it. Already he has been Man of the Match in three of the four Tests. Johnson has 31 wickets for the series and he needs only four more to break the Australian record for most wickets by a fast bowler in a five-Test Ashes, and seven to break Bill Whitty’s record of 37 for most by an Australian fast bowler in any five-Test series, set against South Africa in 1910-11. Clarrie Grimmett’s all-time Australian record of 44 wickets in a series is probably safe, but the way Johnson is going, nothing is certain.

Last week, Scott Borthwick was getting ready to head off to Sri Lanka with England Lions after his stint with the Sydney grade side Northern District. Now, he’s almost certain of making his Test debut at the SCG. Swann’s retirement, combined with a calf injury sustained by Monty Panesar at training, should mean Borthwick is given a chance at Test level. Borthwick has four first-class centuries to his name but unlike Australians such as Steven Smith and Cameron White, he considers himself a legspinner who can bat a bit. If he plays, Borthwick will be the fourth spinner used by England in the space of six Tests, after Swann, Panesar and Simon Kerrigan.

Two days out from the match, the pitch appeared to have more grass on it than a normal Sydney surface and it is expected to offer some assistance for the fast bowlers. The forecast throughout the match ranges from 22C to 27C with the possibility of occasional light showers, but rain shouldn’t play too much of a part.

It is not out of the realms of possibility that Australia will play the same XI for the fifth consecutive Test and there is a strong push from the players to complete the series with the team intact. Shane Watson’s groin niggle and Ryan Harris’ general soreness could be the catalysts for conservatism, with a South African Test tour in a month. Nathan Coulter-Nile will be a direct replacement for Harris if he is ruled out, while Watson’s ability to bowl may determine whether James Faulkner and No.3 Alex Doolan play, and thus whether Bailey can retain his spot. But there would be something very special about completing a 5-0 win with only 11 players, and it may yet happen.

“Yes, we could do. Certainly there will be some changes,” Alastair Cook said when asked if England might play three debutants at the SCG. Such a scenario might have seemed laughable before the series but it’s now anyone’s guess what England’s best XI is. Gary Ballance is likely to be included, given England’s poor batting throughout the series, and it might be that Michael Carberry makes way with Joe Root to move up to open and Ian Bell to No.3. The legspinning allrounder Borthwick would also strengthen England’s batting if he replaces Panesar, while Boyd Rankin could be given a chance at the expense of Tim Bresnan. But, really, who would know?

Australia (possible) 1 Chris Rogers, 2 David Warner, 3 Shane Watson, 4 Michael Clarke (capt), 5 Steven Smith, 6 George Bailey, 7 Brad Haddin (wk), 8 Mitchell Johnson, 9 Peter Siddle, 10 Ryan Harris, 11 Nathan Lyon.

England (possible) 1 Alastair Cook (capt), 2 Joe Root, 3 Ian Bell, 4 Kevin Pietersen, 5 Gary Ballance, 6 Ben Stokes, 7 Jonny Bairstow (wk), 8 Scott Borthwick, 9 Stuart Broad, 10 James Anderson, 11 Boyd Rankin.