England captain Michael Vaughan is in serious doubt for the Ashes after it was confirmed he will undergo another knee operation and miss four to six months of cricket.
The operation will be Vaughan's fourth on his troublesome right knee, and with the Ashes starting in November, just five months away, his recovery would need to be rushed.
England and Wales Cricket Board (ECB) chief medical officer Dr Peter Gregory said Vaughan had done all he could to avoid another operation, but was left with no choice after the injury flared up during a county game.
"Michael worked extremely hard with the support of the Yorkshire medical staff to strengthen the knee to the point where he was able to begin playing again," Gregory told AFP.
"However, he has still been experiencing some discomfort in the knee and further surgery is necessary if he is to regain the level of fitness required for international cricket.
"Our priority now is to safeguard Michael's long-term interests and ensure that he can resume his playing career.
"He will have our full support and we will be closely monitoring his progress in conjunction with the staff at Yorkshire who will supervise his day-to-day rehabilitation program."
Vaughan led his side to a stunning 2-1 victory in last year's Ashes but has not played again at a national level since he was forced home during England's tour of India.
The Yorkshire batsman's knee problem then again resurfaced during a county match against Sussex in which he was unable to field for most of the match, and specialists later confirmed he would need an operation to repair the articular cartilage in his knee.
England coach Duncan Fletcher expressed his sympathy for his captain.
"I really feel for Michael. He is so keen and passionate about playing for England and really wants to get out there and score runs for us again," he said.
"There was no messing around for him, he did everything properly and it's desperately bad luck that he now has to have an operation.
"He just loves batting and scoring runs and to have that taken away must be very hard for him.
"He is desperate to get back playing again and we all are hoping the operation is successful and he can return for England."