In 2014 Diarra left Lokomotiv Moscow one year into a four-year deal and the club took the matter to FIFA's Dispute Resolution Chamber (DRC), arguing he had breached the rules when his contract was terminated after the player decided to leave without just cause following a pay cut.

Diarra received an offer to join Belgian club Charleroi but the club backed out after FIFA refused to sign the International Transfer Certificate (ITC), preventing the player being registered with the Belgian federation.

In 2015, FIFA ordered Diarra to pay 10 million euros ($11.05 million) in damages to Lokomotiv, prompting the former Chelsea, Arsenal and Real Madrid player to sue the world governing body and Belgian FA for damages before a local court. The CJEU ruling could also lead other players affected by the FIFA regulations like Diarra was to also seek damages.

"All professional players have been affected by these illegal rules (in force since 2001!) and can therefore now seek compensation for their losses," Diarra's lawyers Jean-Louis Dupont and Martin Hissel said in a statement.