"I have real hope I'll get better. I'll do all the hard work and I believe there'll be another day when Michael Vaughan takes the field in an England cricket shirt.

"But I have to be realistic. I've read I might never play cricket again -- and that might well turn out to be the case," he was quoted as saying in the British media on Sunday.

"There are no guarantees. I know that better than anyone," added Vaughan, who attended England's sparkling second Test win over Pakistan at Old Trafford on Saturday on crutches.

"There is an area of the knee that's very worn -- and there was a split in the cartilage. They tell me the operation has been successful but they'll only know for certain after rehab."

"What is certain is that whether I play cricket again or not I am going to need a total knee replacement in 15 years."

Yorkshire batsman Vaughan, who led England as they clinched the Ashes for the first time in 18 years in 2005, is recovering from having a fourth operation on his injured right knee on July 3.

The England and Wales Cricket Board (ECB) said he would be targeting a return early in 2007 with a view to being available for the World Cup in the Caribbean in March.

However, 31-year-old Vaughan was still holding out hope that he may play some part in the Ashes series which starts with the first Test in Brisbane on Nov. 23.

"I have to have a go. I have another three weeks on crutches and then, around September 22 -- 12 weeks after the operation -- I'll try to start a little light running," he was quoted as saying in The Mail on Sunday.

"If all goes well, my aim is to be playing some kind of cricket in late December or early January.

"Is there any chance I might be ready for Melbourne or Sydney? Probably not, but I'm going to hang on to that dream."

Vaughan has not played for England since returning home early from the tour of India in February.