FULLBACK Billy Slater may become Australia's back-up hooker for the remainder of the World Cup after a shattered Kurt Gidley was yesterday told he required knee surgery that would rule him out of the tournament.

Under World Cup rules, teams cannot make changes to the 24-man squad named before the tournament once they have played their first match - leaving the Kangaroos without a genuine utility following Gidley's shock injury.

The Knights star suffered a knock to his left knee after coming off the interchange bench in the second half of Sunday night's 30-6 win against New Zealand but managed to complete the match and thought he had merely suffered a pinched cartilage.

But scans taken in Melbourne yesterday revealed Gidley had torn a chunk out of cartilage that would need to be removed or he could suffer more serious damage, and he is expected to undergo surgery next week.

"It is probably one of the toughest things I've been through," he told the Herald at the team hotel after learning the results of the scan. "There's like a wedge out of my cartilage which goes right down to the bone. Then there's the floating bit of cartilage which is in there. If that gets locked or jammed in there, that can cause havoc to the rest of your cartilage so they're putting my best interests first and ensuring that my knee is going to be right for the next few years."

After deciding against naming a deputy for hooker Cam Smith in their squad, the Kangaroos need to manufacture one and Slater appears to be the most likely option as he has shared the dummy-half duties with his Melbourne captain on occasions this season. Gold Coast halfback Scott Prince is another possibility for the role but he may be required to wear the No.7 jersey in Sunday night's clash with England as Johnathan Thurston is also in doubt after suffering a shoulder injury in his man-of-the-match performance against the Kiwis.

Thurston, who elected to travel with the team to Melbourne after the murder of his uncle in Brisbane last weekend, wants to play after scans last night cleared him of serious damage. The loss of Gidley is likely to lead to a call-up for Brisbane fullback Karmichael Hunt, who would probably start on the bench and fill in for Slater when he moves to dummy half.

"That's what I was picked for - that utility role," Gidley said. "I played a bit of hooker and filled in a few positions when Brent Tate got injured so I'm not sure what is going to happen now."

With his brother Matthew - a member of Australia's last World Cup team in 2000 - having returned from England to watch him play and his parents due to travel to Melbourne for the match, Gidley said he had become "emotional" when he broke the news to them of his injury.

"I haven't been that emotional for a long time, it was pretty devastating," he said. "Ricky Stuart makes a good point each time I have been in camp that every Test jumper you can get is a special one so the more you've got hanging in your wardrobe when you retire is pretty special. That's why it cuts so deep.

"Also, the next World Cup isn't for another five years and who knows where I will be then. This could be the only World Cup I play in so that's pretty disappointing."

Gidley will stay with the Kangaroos until Monday when they travel to Townsville. The surgery next week would have sidelined him for six weeks if he was playing but will have little impact on his pre-season preparations with the Knights. England coach Tony Smith said the loss of Gidley was a blow to the Kangaroos but he felt sorry for the Newcastle fullback.

"He's a very great player and a great person so I wouldn't wish that upon him," said Smith, who indicated he would today name injured winger Lee Smith and give him until Sunday to recover from a knee injury.

■ France have lost hooker Julian Rinaldi (fractured cheekbone) for the rest of the tournament.