A Luxembourg court may succeed where financial prudence has failed: stopping football clubs spending millions on transfers. On Friday, the Court of Justice of the European Union will hear the case of Lassana Diarra, 39, who once played for Chelsea and Real Madrid, before moving to Anzhi Makhachkala and Lokomotiv Moscow. A breakdown in relations at Lokomotiv led to the club suing Diarra for his €20 million transfer fee. Eventually Fifa, the sport’s governing body, banned Diarra from playing and ordered him to pay €10.5 million compensation. A Belgian club, Charleroi, offered to take Diarra but wanted guarantees it would not be liable for the compensation. Fifa refused and withheld Diarra’s transfer certificate. Diarra’s case against Fifa’s right to do this is being made by the same lawyer who successfully brought the case that swept away restrictions on players’ freedom of movement 30 years ago. If Diarra wins, it could spell the end of transfer fees.