Benfica’s Gianluca Prestianni has received a provisional one-match suspension after Real Madrid’s Vinicius Jr reported alleged racist abuse during last week’s Champions League meeting.
It means the Argentine winger is set to miss the second leg of the tie in Madrid on Wednesday (20:00 GMT).
Uefa has imposed the ban on a provisional basis, pending the result of a full investigation by an ethics and disciplinary inspector.
The European governing body said further punishment could be handed out once that investigation is completed.
Vinicius told referee Francois Letexier that he had been racially abused by the Argentina winger during the first leg of their Champions League knockout phase play-off tie in Lisbon last Tuesday.
Prestianni has denied racially abusing the Brazilian, and Benfica said they would appeal against the decision despite the belief it is unlikely to have any “practical effect” before Wednesday’s game.