Antoine Griezmann looks set to leave Atletico Madrid next summer after four seasons with the club.His manager Diego Simeone confirmed the news Atleti fans have been dreading, admitting that the Frenchman needs to grow like ex-players Diego Costa and Arda Turan did when they left.Griezmann has helped Los Rojiblancos return to form in recent weeks with three goals in as many games, though he has only managed five in La Liga in 13 outings.Atleti remain unbeaten domestically this term, but their six draws from 16 matches leaves them six points behind leaders Barcelona, with Valencia and Real Madrid back in third and fourth.They were disappointing in the Champions League though, failing to win a game as they exited for the Europa League, with Qarabag of Azerbaijan holding them to two draws despite having ten men on both occasions.Simeone's men will fancy their chances in the Europa League though, having reached the Champions League final twice in the last three years.They will face FC Kobenhavn when the competition resumes in February, with nine potential matches standing between them and European glory.And with five wins from six games in La Liga, they're certainly hitting form at the right time.The title race may be about to heat up even more though, after news broke that Atletico are set to report Barcelona to FIFA over an illegal approach for Griezmann.According to the BBC, no clubs in England have had any complaint registered against them.

Griezmann was heavily linked with Manchester United last summer, before he signed a new contract at the Wanda Metropolitano, as he said it would have been a "dirty move" to leave, with Atletico under a transfer ban.

But Barcelona will clearly be a very tempting proposition for the former Real Sociedad man, who has only won the Spanish Super Cup during his stay in Madrid, and at 26-years-old will be hugely ambitious to add some silverware.

Los Rojiblancos are unhappy with their title rivals though, and believe the approach was made with the intention of turning Griezmann's head and ultimately destabilising their title charge.

If Barca are found to be guilty of tapping up the player, they will likely be hit with a hefty fine.