Australia captain Ricky Ponting is out of the last Ashes Test in Sydney after fresh problems emerged with his injury.
Ponting first fractured the little finger of his left hand during the third Test in Perth and played in Melbourne with it heavily strapped.
But an X-ray on Wednesday revealed it had been damaged again during his side's defeat in the fourth Test.
Vice-captain Michael Clarke will take over in Sydney next week, with Usman Khawaja coming in for his Test debut.
The setback now means Australia must attempt to square the series without their figurehead and best batsman of the last decade.
England retained the Ashes on Wednesday after beating the Australians by an innings and 157 runs in the fourth Test at the MCG with a day to spare.
The news completes a miserable few months for Ponting, who scored only 113 runs in eight innings in the series with an average of 16.14 and faced a barrage of criticism in his own country for his team's dismal performances as well as his own form and personal conduct.
"I'm devastated to tell you the truth, it was the news I was dreading," said Ponting, who broke the finger attempting a catch during the third Test in Perth. "During the game I didn't think I'd done too much more to it."
With Clarke taking over as skipper for the Sydney showdown which starts on Sunday night UK time, other Australian changes see the introduction of Pakistan-born batsman Khawaja, 24, and Doug Bollinger replacing another injury victim, Ryan Harris.
Khawaja, a left-hander who plays for New South Wales, has a first-class average of 51.70 and will be the first Muslim to play for Australia.
Wicketkeeper Brad Haddin has been named as vice-captain for the match, while Cameron White will take on that role for the one-day and Twenty20 internationals.
With Ponting now 36 and Australia's next Test match not scheduled to take place until August 2011, there must now be a real possibility that his long and stellar Test career could be at an end.
Ponting has played for his country 152 times in the longest form of the game and recorded 99 wins, and while he will hope to be part of the Australian team for the one-day World Cup this spring, the selectors may decide to rebuild the Test team without him.
With Ricky being unavailable we are sure that Michael and Brad will lead this Australian side with great professionalism and the full support of the team
Chairman of selectors Andrew Hilditch
Team physiotherapist Alex Kountouris said: "Ricky Ponting had a repeat X-ray after the fourth Test which showed evidence that the fracture of his fifth finger has moved during the course of the Melbourne Test.
"As such he needs to commence treatment immediately to achieve a satisfactory outcome. The treatment options include surgery or aggressive splinting and immobilisation of the injured finger. A decision on the treatment option will be made in the next 24 hours after further consultation with the hand specialist.
"His return to cricket will be based on how quickly the fracture heals and he will hopefully commence training in the later part of the Australian summer. He is expected to be fully fit for the ICC Cricket World Cup."
Chairman of selectors Andrew Hilditch said there was disappointment at failing to win back the Ashes but they were looking forward to the challenge of trying to level the series at the Sydney Cricket Ground.
"With Ricky being unavailable for this match we are sure that both Michael and Brad will lead this Australian side with great professionalism and the full support of the team as we strive for a victory in Sydney," Hilditch added.
"We look forward to Ricky completing his recovery and leading this team to a fourth successive World Cup on the sub-continent at the completion of the Australian summer."