BRUSSELS (AP) — FIFA rules on transfers can conflict with European Union legislation relating to competition and freedom of movement because they limit possibilities for players to change clubs, and for clubs to hire, a senior EU legal adviser said on Tuesday.

Advocate General Maciej Szpunar gave his opinion after French soccer player Lassana Diarra legally challenged FIFA rules.

The Diarra case went through FIFA judicial bodies before the 2016 election of FIFA president Gianni Infantino, who has made it a priority to modernize transfer market rules.

Former France international Diarra signed a four-year contract with Lokomotiv Moscow in 2013. The deal was terminated a year later after Diarra was unhappy with alleged pay cuts.

Lokomotiv Moscow applied to the FIFA dispute resolution chamber for compensation and the player submitted a counterclaim seeking compensation for unpaid wages. The Court of Arbitration for Sport found the Russian club terminated the contract with Diarra “with just cause” and the player was condemned to pay 10.5 million euros ($11.2 million).