FIFA said on Tuesday it has opened disciplinary proceedings against Pachuca player Gustavo Cabral following an incident involving Real Madrid’s Antonio Rüdiger during their Club World Cup match on Sunday, which prompted the activation of the anti-discrimination protocol.

“Following an assessment of the match reports, the FIFA Disciplinary Committee has opened proceedings against CF Pachuca player Gustavo Cabral in relation to the incident involving him and Real Madrid’s Antonio Rüdiger during the FIFA Club World Cup game played in Charlotte on June 22,” FIFA told Reuters.

Match referee Ramon Abatti activated the anti-discrimination protocol by crossing his forearms in front of his chest five minutes into stoppage time after a brief scuffle erupted following an apparent foul on Germany international Rüdiger.

Asked during a post-match news conference if Rüdiger had been a victim of racism, Real Madrid coach Xabi Alonso said: “That’s what Rüdiger said, and we believe him.”

FIFA did not specify the nature of the disciplinary action.

Cabral has denied that he racially abused the Madrid defender.

“There was nothing racist. I called him ‘chickens—‘ as we say in Argentina, that’s it,” Cabral told reporters in Spanish after the game.

Information from Reuters was used in this report.