International soccer faces a bleak future if a landmark court case seeking compensation for player injuries suffered on national team duty is successful.
The warning came from European governing body UEFA on Friday in the light of Belgian club Charleroi's decision to sue FIFA after their player Abdelmajid Oulmers was injured playing for Morocco in 2004.
If the case is successful, and clubs become entitled to compensation while their players are away on international duty, there are fears that most countries would be unable to fund national teams.
"It would be the end of the national team game. A World Cup would take place with only Spain, Germany, Italy, France and England," UEFA spokesman William Gaillard told the BBC.
Gaillard said international soccer was "in the end what people like the most."
"If you ask the English fans if they would like to see one English club win the Champions League or England win a championship, then I think you know the answer," he said.
Charleroi are claiming the loss of Oulmers damaged their hopes of winning the Belgian league title in 2004/05 and it wants compensation for having to pay the player's wages while he was out of action.
In May, the case was moved from a tribunal in Charleroi to the European Court of Justice, where it is waiting to be heard.
The club are being backed by the powerful G14 group of clubs, who are unhappy with FIFA rules that players must be released for international soccer without entitlement to financial compensation.
A Charleroi victory "would be the end of national football for any football association outside of the big five in Europe," Gaillard said.
"I was talking to Brazilian, Scandinavian and Eastern European football experts, and they all said we would never see our stars playing for the national team again. A World Cup would take place with only Spain, Germany, Italy, France and England and that would be the end," he said.
However, Arsenal manager Arsene Wenger said on Friday that it would be difficult to prove how an injury occurred.
Wenger referred to the ongoing row between Newcastle and the English Football Association over compensation after Michael Owen was injured playing for England during the World Cup.
"I'm not certain that the English federation is responsible for this injury," the Frenchman said. "Perhaps he would have been injured in the same way if he had stayed at Newcastle," he said.
"A player can have a knee problem one day, then go elsewhere and nothing happens for years, before his knee finally gives way. Injuries are part of the risks of the job, we have to accept that," Wenger said.