Black players could boycott the 2018 World Cup in Russia if the country does not tackle racism in the stands, ManchesterCity's Ivory Coast midfielder Yaya Toure was quoted as saying on Friday.
Toure, whose allegations that he was a victim of racist abuse during Wednesday's 2-1 Champions League victory at CSKA Moscow have prompted UEFA to open disciplinary proceedings against the Russian club, said FIFA and Russian authorities needed to act.
"It's very important," British media quoted him as saying.
"Otherwise we are not confident coming to the World Cup in Russia. We don't come."
The episode has been embarrassing for European soccer's governing body UEFA, who had declared this week 'Football Against Racism in Europe Action Week'.
It has been criticised by world players' union FIFPro for failing to enforce its own guidelines, under which match officials have the power to stop and abandon games in case of a serious incident.
CSKA have denied Toure's allegation, saying they were "surprised and disappointed" by it.
Toure, who speaks Russian after spending two years playing in Ukraine for Metalurg Donetsk, said the abuse he experienced in Moscow was worse than anything he encountered in Ukraine.
"We had some racism in Ukraine, but maybe only one, two or three people, not in groups like that (on Wednesday)," he said.