Real Madrid’s Thibaut Courtois would “welcome” players being sanctioned for covering their mouths when speaking to opponents if it helped end on-pitch racist insults.

The goalkeeper was speaking after his team-mate Vinicius Junior alleged he was racially abused by Benfica’s Gianluca Prestianni in the first leg of the Champions League play-off last week.

Prestianni, who has denied racially abusing Vinicius Jr, covered his mouth with his shirt at the moment of the Brazilian forward’s allegation.

“If it put an end to the insults, I’d welcome it. If it put an end to racism, I’d have no problem at all with the idea,” Courtois said at a news conference on Tuesday.

“With Prestianni, it’s complicated because it will always be one person’s word against another’s. We are 100 per cent with Vinicius, who has suffered a lot from this )racist abuse) but, with the mouth covered, you can never know absolutely, and Benfica are bound to defend their player. It’s down to UEFA and the institutions to act.”

Courtois admitted such a move would be “complicated” but said football lacked the transparency of other sports with on-pitch communication: “In many sports, players are wearing microphones, as referees do. And so you can hear everything.”

Prestianni will miss the second leg of the Champions League play-off in Madrid on Wednesday after being provisionally suspended “without prejudice” by UEFA for one match. Madrid hold a 1-0 lead from the match in Lisbon.

Last week’s first leg was stopped for around eight minutes after Vinicius Jr, 25, alleged that Prestianni, 20, had abused him following the Brazilian’s second-half goal. After speaking to Vinicius Jr, referee Francois Letexier signalled the start of FIFA’s racial abuse protocol by crossing his wrists above his head.

The following day, UEFA — European football’s governing body, which organises the Champions League — confirmed it would be opening an investigation into the alleged offence, which carries a minimum suspension length of 10 games if proven.