Atletico and Gelson Martins the latest Sporting transfer brought before FIFA Transfer Market - Atletico Just like Wolves' Rui Patricio deal

The mess that resulted in the training ground attack by Sporting CP ultras on the club's squad is set to continue with Atletico Madrid's free transfer of Gelson Martins to be taken to FIFA.

Just like Rui Patricio's move to Wolves, the governing body have received an official complaint from the Lisbon club, who dispute the legality of those players rescinding their contracts in the attack's aftermath.

Foreseeing a potential issue, Atletico sought clarification from FIFA and pressed ahead with the signing of Martins regardless, confirming the deal on Wednesday.

Los Colchoneros had been in talks with Sporting to settle on an amicable transfer of the player, with an offer of 15 million euros plus 50 percent of any future sale put forward.

Alas, the Portuguese team held out for 20m euros, half of his 40m euro release clause, and rejected the chance to take Luciano Vietto and goalkeeper Andre Moreira on loan as part of the deal.

The basis of Sporting's complaint to FIFA is that Martins was not one of the players confronted by the ultras at the end of last season and thus has no grounds to rescind his contract.

It is now up to world football's governing body to give a definitive answer to one of the summer's biggest market subplots.