AC Milan midfielder Kevin-Prince Boateng -- lauded for walking off the pitch to protest abuse by fans -- on Thursday called for an end to racism in the sport, likening it to a virulent disease that blighted the game.
The 26-year-old Ghana international told a United Nations anti-discrimination meeting in Geneva that he had repeatedly tried to ignore racism from fans during his career but concluded that the only way to stop it was to tackle it head-on.
"Racism doesn't go away. If we don't confront it, it will spread," he told delegates.
"The big problem with racism is that there is no vaccine for it. There are no antibiotics that you can simply take. It is like an extremely dangerous and contagious virus. It is emboldened by our indifference and inaction."
Boateng's stand against racism has been seen as a watershed in how the problem is tackled, amid debate about whether football's world governing body FIFA and its European counterpart UEFA, as well as clubs, were doing enough to eradicate it.
The Berlin-born playmaker, whose mother is German and father Ghanaian, made headlines worldwide in January when he stormed off the pitch 26 minutes into a friendly against Italian fourth division club Pro Patria.
His team-mates followed him in a gesture of solidarity.
He said on Thursday that he had never planned to make a stand and had cracked after facing non-stop abuse from kick off but acknowledged the symbolism of his action.
"We, who are constantly in the public eye, have more responsibility than others. We cannot afford to be indifferent or passive," he explained.
After Boateng's protest, the Italian league said that although the rules did not allow a team to leave the pitch without a referee's consent, it would not sanction a player abused for his skin colour.
Boateng climbed up the Germany youth ladder before being capped by Ghana at the 2010 World Cup -- and he likened his stand against discrimination and intolerance to the fight against disease.
"When I played for Ghana I learnt how to combat malaria. Simply inoculating people is not sufficient. You also need to dry out the swamp where the mosquitoes that spread malaria breed. I think that malaria and racism have a lot in common," he said.
"Football stadiums can be places where people with different ethnic backgrounds come together to cheer on their team or a dangerous swamp where healthy people can become infected with racism.
"We cannot allow racism to spread right in front of our eyes. Football stadiums and many other places are full of young people. If we don't dry up the swamp, many of them who are still healthy today will catch one of the most dangerous viruses of our time."
Boateng is due to meet FIFA president Sepp Blatter on Friday. Blatter has raised concerns about players taking matters into their own hands but has since said clubs whose fans are guilty of racial abuse could be either docked points or relegated.
FIFA has created an anti-racism taskforce, whose head Jeffrey Webb has called existing sanctions to defend racially-abused players a "travesty".
"Despite the many victories we have won in football against discrimination and prejudice, we know we still have a problem today and we know more has to change," FIFA's head of corporate social responsibility Federico Addiechi said here on Thursday..
UEFA president Michel Platini applauded Boateng's protest from the outset.
"We have given referees the power, and the duty, to stop the game if they feel the game is being polluted by racism," UEFA official William Gaillard told the UN.
UN human rights chief Navi Pillay said the sports world needed to strike hard.
"Such incidents are illegal. Sporting events are bound to comply with the provisions of international human rights law. Racism violates that law," she said.