Italy's Manchester City forward Mario Balotelli (pictured right) said he would walk off the pitch if he heard racist abuse coming from the stands but UEFA president Michel Platini warned it is up to the referee to take the teams off, and that players who took matters into their own hands would be punished.
Ruud Gullit: "The monkey sounds that greeted the Holland team at their training session this week were an embarrassment to the Polish authorities.
"The problem of racial abuse of footballers is now on everyone's radar and it has to be dealt with.
"UEFA have given referees the power to stop a game and I am behind that. The problem needs to be tackled straight away, so players shouldn't just keep quiet and play on like in my day.
"It has been suggested by the UEFA president Michel Platini that players would be booked for leaving the field as an act of retaliation and defiance. That, in my opinion, is the wrong message.
"If a player is racially insulted, he should have the right to leave the field. I would like to think we can trust referees to take everyone off but, if the officials are not supporting the players correctly, then the individual should act. The message this would send out: 'we will not tolerate this abuse'.
"When I played, I received racial abuse but I was just one of a few black players and we weren't backed up by the authorities.
"I used to ignore the abuse and felt powerless to change attitudes. My only weapon was my performances on the pitch.
"We are beyond that now though. We just have to hope that racism doesn't haunt this tournament but that, if it does, the response is strong. The players need the support of UEFA and the football authorities need the support of the police."