Football's most important legal test case since the Bosman ruling began in a Belgium court yesterday with Fifa lined up against Europe's richest clubs.
The Belgium first division side Charleroi are claiming £426,000 compensation for one of their players injured in an international friendly and are being backed by G14, the group of 18 elite clubs including Manchester United, Liverpool and Arsenal.
If Fifa lose, it will hand much more power to the clubs who believe they should be paid while players are on international duty.
Charleroi's lawyer Jean-Pierre Deprez told the court the club's chairman Abbas Bayat had been pressurised by Fifa to drop the case.
Fifa spokesman Andreas Herren confirmed the organisation's president Sepp Blatter met Bayat on Friday but denied any pressure was applied.
Herren told PA Sport: "The meeting took place in the presence of the general secretary of the Belgium FA and UEFA president Lennart Johansson. We strongly reject any allegation that pressure was applied or that threats were made."
Charleroi are suing Fifa over the injury to Morocco's Abdelmajid Oulmers, who was out for eight months after injuring ankle ligaments against Burkina Faso in November 2004.
They claim Fifa are liable because under their rules they oblige clubs to release players for internationals without payment.
Blatter has since tried to achieve a settlement by announcing that Fifa will cover insurance costs for players during the World Cup, but G14's ultimate aim is for clubs to be reimbursed the players' wages while they are on international duty.
G14 are also backing a similar legal claim from one of their members Lyon over their France defender Eric Abidal who broke his foot in a friendly.
G14's general manager Thomas Kurth said: "The current regulations favour national associations and expose clubs to serious damages."
Meanwhile, Barcelona vice-president Ferran Soriano has claimed G14 want to increase the number of Champions League matches.
UEFA's scrapping of the second group phase in 2003 has been widely welcomed but was opposed by G14.
Soriano told BBC Sport: "We are not talking about doubling the number of games, it may be adding just one or two.
"We have to have the opportunity to participate in the final decision.
"The last time it was changed from two group stages to one we couldn't say anything and that can't happen again.
"In general terms the Champions League is a fantastic competition but we want to have more games if possible."Reuse content