If the complaint is rejected, the Belgian agent and lawyer could then appeal to the European Court of Justice.
The process could take between one and three years.
"Any person or party -- as the English Football Association or the English Premier League or individual clubs -- who can prove an interest in the outcome of a case may apply to join into in the proceedings," said lawyer Guy Thomas of English firm Taylor Walton.
"It sounds like there will be a lot of potentially "interested" parties for this one," added Thomas. "If they all try to get involved the proceeding could be delayed even longer.