LEVERKUSEN, Germany — Bayer Leverkusen is taking its fight to sign Argentine striker Lucas Alario to FIFA.

The Bundesliga club said on Friday that the Argentine soccer association (AFA) has refused clearance for the 24-year-old player to join from River Plate despite the payment of his release clause.

Leverkusen said it has “no understanding” for the AFA or River Plate’s position, and that it had applied to FIFA for Alario to be registered as one of its players. It added that it is confident “Alario will soon be able to play” for the club.

River Plate contends the transfer is invalid as Leverkusen paid the release clause of 23.8 million euros ($28.6 million) on Aug. 31, after the Argentine season had begun, which it claims is against FIFA rules.