National hero Jonny Wilkinson will miss England's celebration match against the New Zealand Barbarians next week because of a neck injury, his club Newcastle said.
Celebrating the World Cup
London pours into the streets
England take the Cup north
Wilkinson fulfils his destiny
A welcome for heroes
The tests revealed 'an area of concern' that has ruled him out of Newcastle's European Shield match against Spanish side Valladolid on Sunday.
The injury, which the club said was not connected with the player's car crash last Monday, will require further tests, but seems likely to keep him out of England's game against the New Zealand Barbarians at Twickenham on December 20.
The news completed a remarkable week for Wilkinson, which began on Monday in London with 750,000 people cheering him and his England teammates during the squad's official victory parade.
After meeting the prime minister and the queen, he escaped unhurt when the car in which he was a passenger hit a tree as he headed back to Newcastle.
He returned to London on Wednesday to accept an MBE from the queen before being named in the Newcastle team for Sunday's match.
The 24 year-old, hot favourite to be named the BBC's Sports Personality of the Year on Sunday, has had problems with his neck for several years.
He even suffered a scare in the World Cup final against Australia when a tackle in the first half led to a burst of shoulder pain that he feared would force him off the pitch.
Meanwhile, coach Clive Woodward announced a squad that includes just five members of the World Cup-winning team for the match against the Barbarians.
The England XV will play the invitational side on December 20 in a non-cap game primarily meant to give home fans a chance to salute the players who lifted the Webb Ellis Trophy in Sydney.
But of the World Cup final starting XV, only Jason Robinson, scorer of England's solitary try in the 20-17 win over Australia, Mike Tindall, Richard Hill, Steve Thompson and Phil Vickery have been included in the 22 member squad. Fullback Iain Balshaw and back rower Lewis Moody, who both came on as replacements in the final, have also been included.
Notable by their absence, apart from Wilkinson, are captain and lock Martin Johnson, number eight Lawrence Dallaglio, centre Will Greenwood, and scrumhalf Matt Dawson. Vickery will lead the side.
"I have selected a very strong England XV squad to prepare for the game and it's the most experienced of all the teams I've selected to face a Barbarians side," Woodward said. "It contains players with nearly 500 caps between them and it's a game which gives all those taking part a fantastic opportunity to make a positive statement ahead of the 2004 Six Nations Championship.
"The squad includes 15 of the 31 from the World Cup... although I can't pick a full-strength team as the game isn't a Test match under IRB rules, it will be great to see Charlie Hodgson and James Simpson-Daniel back playing at Twickenham."
But the whole England squad, including Johnson, Wilkinson and Dallaglio, will be parading the Webb Ellis Cup around the stadium for a lap of honour after the game.
The day will also feature a presentation to prop Jason Leonard to commemorate his world record 113th cap and to Wilkinson and scrumhalf Kyran Bracken, who both earned their 50th caps during the World Cup.