International football will be destroyed if Belgian club Charleroi win a landmark court case, says European football's governing body Uefa.
Would a Charleroi win mean the end of Keane in a Republic of Ireland shirt?
Charleroi are suing world body Fifa after player Abdelmajid Oulmers was injured playing for Morocco in 2004.
Few countries could fund national teams if Charleroi won, Uefa told BBC Sport.
A spokesman said: "It would be the end of the national team game. A World Cup would take place with only Spain, Germany, Italy, France and England."
A Charleroi victory would mean clubs would become entitled to compensation while their players are away on international duty
The spokesman, William Gaillard, said international football 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.
Watch full interview on BBC1's Six O'Clock News on 13 October
Charleroi claim the loss of Oulmers damaged their hopes of winning the Belgian league title in 2004/5 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 G14 group of clubs, who are unhappy with Fifa rules that players must be released for international football 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.
What the national coaches are doing is like taking the car from his (club manager's) garage without even asking his permission
"Recently the head of the Irish FA said if we have to pay for our stars we would never see Robbie Keane playing for Ireland again.
"There's no way the Brazilian FA could pay for one fifth of the players."
Newcastle are negotiating with the Football Association for compensation after Michael Owen was injured playing for England during the World Cup.
The FA has one of the most progressive insurance policies in world football, offering to pay the wages of players for up to two years after they suffer injury.
The sums involved are reported to be capped at £55,000 a week.
Arsenal boss Arsene Wenger this week weighed into the debate by likening international coaches to joyriders.
"What the national coaches are doing is like taking the car from his (club manager's) garage without even asking his permission," Wenger said.
"They'll then use his car for 10 days and abandon it in a field without any petrol left in the tank.
"We then have to recover it, but it is broken down. Then, a month later, they'll come to take your car again -and for good measure you're expected to be nice about it."