Michael Vaughan could miss England's next two warm-up matches after suffering a setback on his comeback from injury.
The opener underwent knee surgery at the end of the domestic season in a bid to be fit for the start of the tour of Australia.
But on Wednesday he was ruled out of England's two-day match against Western Australia to further exacerbate coach Duncan Fletcher's injury crisis.
On Tuesday, England all-rounder Andrew Flintoff was sent to the National Academy in Adelaide in a bid to speed up his rehabilitation from hernia surgery.
Australia captain Steve Waugh cannot wait for the Ashes series to start after humbling Pakistan in a 3-0 whitewash.
Waugh has warned England his team are at the top of their game.
They beat Pakistan with ease, recording two innings victories in the three Tests.
Waugh said after winning the final Test in Sharjah on Tuesday: "It's a big thing to play for Australia and we can never be complacent.
"I was a bit surprised we won the last two Tests so easily, but overall it was an excellent performance.
"We are ready to go for the Ashes."
Darren Lehmann knows he's close to Test selection but admitted today it will take a "tough call" to oust Mark Waugh.
Lehmann flew into Adelaide from Sharjah today, released early from the Australian squad to lead South Australia against NSW in the Pura Cup match from Friday.
After sitting through the three-Test series against Pakistan, it's his one chance in a four-day match to show he's in the right form to earn selection for the first Test against England at the 'Gabba strating on November 7.
If he gets the nod, it will almost certainly come at the expense of Waugh, who has endured another disappointing series against Pakistan.
"Everyone's dream is to play in an Ashes Test series," Lehmann said.
