England's biggest worry? It's our main strike bowler Steve Harmison

Marcus Trescothick was an obvious concern, along with the two wicketkeepers, but it's not difficult to make an argument for Harmison holding the key to the series.

At the start of the English 2005 season he was feeling his way back to form and fitness in the Durham team under the captaincy of Mike Hussey.

It's hard to believe now that Harmison went on to play a big role in that summer's Ashes triumph, while Hussey, at 30, had yet to make his Test debut.

In their brief time as teammates they both contributed hugely to Durham winning their first four championship matches, which provided the perfect launching pad to secure promotion.

Now they will oppose each other and there is a perception that if Hussey has a weakness it is against a short-pitched ball which climbs more steeply than he expected. No-one is better equipped to deliver that than Harmison - when he's on song.

Other than when he exploited the extra bounce in the Old Trafford pitch to destroy Pakistan last summer, the Ashington Express has been off key since bowling coach Troy Cooley switched camps.

Now the Australians will benefit from Cooley's expertise, not to mention his knowledge of the England players, while his successor, Kevin Shine, tries to work out how to get the best out of his charges.

The man who oversaw Somerset's slide from division one runners-up into a mid-table second division side has yet to convince anyone outside the England set-up that he possesses anything more than the requisite coaching badges.

There ought to be enough talent among the England batsmen to post competitive totals. But the bowling remains a worry against a batting lineup which is all the more formidable for Hussey's presence.

He has taken the place occupied during the 2005 series by another former Durham man, Simon Katich, while the supremely talented Michael Clarke was to be ditched to make room for all-rounder Shane Watson until the latter strained a hamstring.

The fact that Australia were able to ignore the brilliant Darren Lehmann, and still have the likes of Katich, Phil Jaques and Brad Hodge in reserve underlines an astonishing depth of talent.

Suspicions that their bowling attack was creaking may also be unfounded, although it will be interesting to see whether Shane Warne can regain top form as he was certainly below his best for Hampshire last summer.

Glenn McGrath can't go on much longer and Jason Gillespie appears to be a spent force, but top-quality replacements are emerging in the shape of Shaun Tait, Mitchell Johnson and Stuart Clark.

As a left-armer Johnson would provide variety, but it looks as though Australia are more likely to go for Tait, who has barely looked back since his one-month disaster with Durham at the end of the 2004 season, when his run-up went walkabout. With his pace and reverse swing he could have the sort of impact that Simon Jones had in the 2005 series.

To what extent England miss Jones depends on whether Jimmy Anderson can fulfil the promise which first brought him into the squad three years ago. There have been occasional glimpses of real quality, but now he needs to perform consistently.

As does Harmison, whose career has been a real rollercoaster.

No-one has doubted his threat since he made his Durham debut at 17, but periods of high achievement have alternated with spells when he has completely lost his radar.

Questions are still asked about his state of mind, partly because he doesn't like to leave Ashington and also because he still admits he'd rather have been a professional footballer.

But there's no doubt he relished the last Ashes series, and if he is similarly inspired by this one he ought to be experienced enough now to work things out for himself, irrespective of Shine's input.

In 2005 the England attack worked superbly as a pack and they will need to do the same again, otherwise Liam Plunkett or Sajid Mahmood could be pitched into something for which their experiences so far have not fully prepared them.

It was a similar situation for Paul Collingwood when he replaced Jones for the final Test in 2005, but he has since blossomed into the finished article.

The fact that he bowled ten overs in the opening one-day match of the tour, while Monty Panesar sent down only three, suggested that England might be thinking of playing both Collingwood and Andrew Flintoff as all-rounders, with only three specialist bowlers.

That would be a defensive approach, however, and as they are not going to hang on to the Ashes by drawing every match, England need to go into every Test believing they can take 20 wickets.

The best wicketkeeper would help them do that, but it appears that Duncan Fletcher has got his own way by opting for Geraint Jones.

Whether Chris Read, the better glove-man, should have been jettisoned on the strength of his brainless batting in the Champions Trophy, is a moot point.

He's a decent batsman, but he hasn't shown it on the international stage.

If Fletcher thinks Jones can provide the required runs at No 7, will he be happy to have Panesar in the team ahead of Ashley Giles?

Probably not because the coach won't fancy a tail reading: Anderson, Hoggard, Harmison, Panesar, but Monty will get a game in place of one of the seamers on the more spin-friendly surfaces such as Sydney.

That's the venue for the fifth and final Test on January 2, so let's hope the series is still alive by then - unless, of course, England have already won it.