By Martin Gough

Michael Clarke and Brett Lee mark 100 days to go

With the countdown commencing in earnest to the start of the Ashes in Brisbane on 23 November, BBC Sport compares the possible starting XIs.

There could be as many as seven changes from the sides that drew at The Oval last September, with England's injuries forcing their hand and Australia making one or two tweaks.

Andrew Strauss
Here is a bold prediction to start with: As Andrew Flintoff takes time to recover from ankle surgery, England will opt for the security of Strauss as skipper throughout the series.

Strauss's record since taking the reins from Flintoff has been good in Test cricket, with two wins from three matches against Pakistan.

After an out-of-sorts start to the summer he has also stepped up with the bat, hitting key second-innings centuries at Lord's and Headingley.

Ricky Ponting
Since the start of 2006, Australia's skipper has hit five centuries in six Tests, including back-to-back tons against South Africa in Sydney.

He may have to use a new bat as his graphite-backed version has been ruled illegal by the game's law-makers but that is unlikely to put him off his stride.

Since the Ashes, he has won 11 of 12 Tests, drawing one with South Africa, and his back-up staff has been bolstered this time around with the arrival of bowling coach Troy Cooley in particular.

Advantage: Ponting

Marcus Trescothick
After leaving England's tour of India in circumstances that are still clouded, Trescothick started the summer with a century at Lord's.

Since then, though, he has cut a distracted figure prone to loose shots outside off stump as he was early in his career.

Matthew Hayden
Many believed Hayden, who will be 35 when this series starts, would not be around for the Ashes rematch after being stymied for much of the summer in England.

Since then he has averaged 58.50, with five centuries, against the ICC World XI, West Indies and South Africa, and his trademark drive could find more success on Australia's hard grounds.

Advantage: Hayden

Alastair Cook
Cook shot to public prominence with a double century for Essex against Australia in a two-day tour match last year and has since taken to international cricket as if to the manner born, with 638 runs from eight Tests.

An old-fashioned batsman, his ability to score runs when not in the best form has also won plaudits and he may be the man to frustrate Australia's attack.

Justin Langer
A bash on the head during his 100th Test, against South Africa in April, has reinvigorated Langer's passion for the game and he will not go into this series under-prepared.

He endured a storming short stay in county cricket with Somerset this summer, with 390 in three first-class innings and a tournament-leading 494 runs in the Twenty20 Cup, although he had never played the format before.

Advantage: Too close to call

Kevin Pietersen
How do you argue with Pietersen's Test average of 48.41? By saying it should be higher as he is prone to getting out to expansive shots once well set, especially after passing the 100 mark.

Although this summer has seen three big centuries against Sri Lanka and Pakistan, he has appeared bored on occasion but the challenge of facing Australia should bring out the best again.

Damien Martyn
Dropped after a woeful Ashes tour last year, Martyn's exile ended in March but he has done little to suggest he will cause England more trouble this time.

His sole century came against South Africa in a dead Test in Johannesburg and he was passed over in favour of Phil Jaques for the final Test in Bangladesh, which could be a hint at the future.

Advantage: Pietersen

Ian Bell
The lowest-profile of England's Ashes-winners has been making waves since coming back into the side for the injured Andrew Flintoff with centuries in three successive Tests against Pakistan.

It will be hard to leave him out of the side even though Paul Collingwood has also presented a strong case for inclusion but Shane Warne for one will be unworried by Bell's threat.

Michael Hussey
Some Aussie observers were crying out for Hussey to be called up in the middle of last summer and when he finally took his Test bow it was easy to see why.

After centuries in his second, third and fifth Tests he currently has a career average of 75.93, his years in county cricket with Northants and Durham mean he knows his opponents well but he is still unseasoned at this level.

Advantage: Too close to call

Andrew Flintoff
As Flintoff's bowling was the key component in England's famous series victory in 2005, they have their fingers crossed over his return to action after ankle surgery.

He is expected to return in mid-October but previous prognoses over his injuries have been optimistic and England must plan at least to open the series with Flintoff's role reduced.

Michael Clarke
The lustre around Australia's golden boy dulled during 2005 and he was dropped for six Tests before returning in Bangladesh in April.

At his best he is a cavalier shot-maker who can take teams apart. At his worst he is frustrated into giving his wicket away when set, especially when the ball is swinging.

Advantage: Flintoff

Chris Read
After two years on the fringes of the side, behind Geraint Jones, Read returned with a vital - if a little ugly - half century against Pakistan a fortnight ago.

England may well find him a tidier gloveman and a more productive scorer than Jones but he is unlikely to be considered worth a place in his side's top six, as Gilchrist can be.

Adam Gilchrist
From the start of the last Ashes series until he faced lowly Bangladesh in April, superhuman Adam Gilchrist was rendered mortal, with just 516 runs in 15 Tests and a batting average less than half his previous career mark of 55.65.

Some point to his advancing age at 34 and his dual workload but the overall feeling is that England worked Gilchrist out, bowling short around the wicket to cramp his shots, and other opponents have followed.

Advantage: Gilchrist, just

Monty Panesar
The legions of fans wearing fake beards highlight his popularity and the 21 wickets in his last four Tests suggest his great potential but Panesar is still green.

He will be placed under massive pressure, especially in the field, by Australia's ruthless fans and their batsmen as they look to exploit his perceived weakness.

Shane Warne
The 2005 Ashes would have been a blowout were it not for Warne's 40 wickets - almost double the haul of any other bowler in the series.

His success has continued since then, including at county level, where he has 44 first-class wickets in 10 games as captain of Hampshire despite nagging shoulder problems.

Advantage: Warne

Matthew Hoggard
Ranked the seventh-best bowler in the world, Hoggard has had a subdued series against Pakistan, with just seven wickets at an average of 49.85, including a wicket-less game at Old Trafford.

His strength is opening the bowling when there is swing available with the new ball but he can struggle to make breakthroughs without the right factors in place.

Glenn McGrath
After he missed tours of South Africa and Bangladesh to be with his wife as she battled cancer, McGrath's ability to return to his best could be a key to the series.

As he is aged 36 and reliant on bowling plenty of overs to find his best form, there are plenty of question marks but McGrath also thrives on proving the doubters wrong and could have one last big series in him.

Advantage: Too close to call

Steve Harmison
After an anonymous 12 months, including time out to overcome a shin injury, Harmison is returning to his best just in time for the Ashes.

On a helpful Old Trafford wicket against Pakistan he showed the pace and hostility that could be vital to Ashes success in taking 11 wickets, and gained some much-needed confidence.

Brett Lee
Lee's success as an opening bowler since he was installed at the start of the last Ashes series makes it all the more surprising that he was left out for 18 months before then.

He was below his best when South Africa toured Australia, his average slipping above 30, but prospered during the return leg on generally helpful wickets.

Advantage: Too close to call

Sajid Mahmood
England have stuck with Mahmood despite his inconsistency, reasoning that they need his 90mph pace if they are to enjoy Ashes success.

He produced a match-winning 4-22 against Pakistan at Headingley but this series may come too early for the Lancashire man, who too often errs short and wide.

Stuart Clark
Seen as the poor man's Glenn McGrath, Clark showed that he could stand in for Test cricket's most successful fast bowler by taking 20 wickets at an average of 15.85 in South Africa earlier this year.

Australia must find a way to work him into the line-up even though that might mean forsaking the pace offered by the likes of Shaun Tait.

Advantage: Clark

Australia win 5-2 on direct comparisons but with four head-to-heads too close to call this series promises to be as unpredictable as the last one.