Martin Johnson finds himself in the rare position of being an England coach finalising his Test selection without having to fret over the fitness of Jonny Wilkinson.

Neither Andy Robinson nor Brian Ashton before him enjoyed that same pleasure too often as Wilkinson spent the years after his 2003 World Cup-winning heroics battling through a succession of 13 injuries.

Whenever Wilkinson was available for England it was, by his own admission, no more than a "funny little cameo" before he was sidelined by another frustrating medical mishap.

In five years, Wilkinson did not play more than six consecutive matches and he was horribly out of sorts on his last start for England, in the 9-3 defeat to Scotland in 2008.

Wilkinson, now 30, is back in prime form and rude health after a revitalising summer move to Toulon and he is certain to start against Australia this weekend.

But it is with a certain cruel irony that while Wilkinson is now fit and firing, Johnson's best-laid plans for the autumn Investec Challenge Series have been ravaged by injuries elsewhere.

England have lost 11 of their initial 32-man senior elite squad, including six who toured South Africa with the British and Irish Lions in the summer plus last year's player of the year Delon Armitage.

Johnson's easiest selection decision will be replacing Riki Flutey at inside centre with Northampton's Shane Geraghty, who has been one of the stars of the Guinness Premiership season to date.

Geraghty is likely to partner Dan Hipkiss in midfield while England will also have to field a new-look back three - with the key decision whether to start with Ugo Monye or Ben Foden at full-back.

Starting with Monye would allow Johnson to retain Matt Banahan and Mark Cueto on the wings and potentially utilise the versatile Foden off the bench.

Up front, England have lost a full Lions front row in hooker Lee Mears, tight-head prop Phil Vickery and loose-head Andrew Sheridan.

Australia's scrum is no longer the splintering wreck it once was but both Argentina and New Zealand are likely to pose England tougher tests later in the series.

This could be the ideal opportunity to start with Bath's tighthead David Wilson, who is highly regarded in the England camp, while a bolder selection still would be to blood Northampton's dynamic lock Courtenay Lawes alongside captain Steve Borthwick.

The clamour for England to start with Lawes has been growing since his destructive Heineken Cup performance against Munster but Johnson may prefer to stick with Louis Deacon or the more experienced Ben Kay.

England's back row has been weakened by Nick Easter's torn calf muscle, leaving James Haskell to compete with Jordan Crane for the number eight position.

Johnson will reveal his hand at mid-day on Wednesday and he insists England have the resources to cope with the challenge from a new-look Australia side, who head to Twickenham on the back of a seventh consecutive defeat to New Zealand.

"We are confident in the group we've got. It's a good blend," said Johnson.

"With the challenges we've got this week, we can be very competitive."