Former Barcelona and Spain midfielder Andres Iniesta has been criticised after posting a photograph of himself with two people in blackface as part of Epiphany celebrations in Spain.
Two of the group are painted black - the role of Balthazar is often played by a white man in blackface in Spain.
Iniesta, who plays for Vissel Kobe in Japan, has not responded to criticism.
"I love Iniesta like few other public figures, let alone athletes, he seems a supremely humble man and team-mate," said journalist and author Musa Okwonga.
"I just wonder how you can share a dressing room and so many trophies with Eric Abidal and Dani Alves and still not realise this is not cool. It's very disappointing."
BBC Radio 1 Extra presenter Nick Bright said: "I cannot believe in 2019 famous people are still doing or are around people doing 'blackface' and tweeting it, where are your friends Iniesta?!
Three Kings Day is an important Christian festive tradition on 6 January in Spain that commemorates the visit of magi Melchior, Caspar and Balthazar to the newborn baby Jesus.
Large parades are held in cities in Spain on 5 January and the Kings are usually councillors, most of whom are white, so Balthazar is frequently played by a white man in black makeup.