The Lazio president, Claudio Lotito, has again denied his club has a serious problem with racism after more abusive chanting marred Saturday's 2-1 win over Cagliari.

During the game, in which the away side's coach, Ivo Pulga, and two of his players were sent off, a section of fans in Lazio's notorious Curva Nord abused the Cagliari player Victor Ibarbo. While the rest of the stadium whistled in an attempt to drown out the chants, the referee warned both captains the match would be suspended if the abuse continued.

"Lazio is always called a racist club which is not true," Lotito told Sky. "We have lots of non-white players. We can't control the actions of individual fans. Coming to these sorts of judgments you risk criminalising thousands of fans for the actions of a few.

"Since I became president ... certain modes of behaviour that were there before are no longer there. We are tough on the fans when they behave in a way that is against the law but today I can say the majority of the fans behaved themselves," Lotito said.

Milan's Kevin-Prince Boateng, meanwhile, is considering leaving Italian football following the racist abuse that prompted him to walk off the pitch during a friendly last week. The Ghana midfielder was followed off the pitch by his team-mates at fourth-tier side Pro Patria after several players were racially abused.

The 25-year-old has been publicly back by Milan, with the club president, Silvio Berlusconi, insisting that his players would always walk off the pitch if they are subjected to further racist abuse. Boateng is now considering whether to leave Italy during this transfer window.

"It's not something which you can just shake off," he said. "I will sleep on it for the next three nights and then sit down with my agent Roger Wittmann next week. We will have to see if it's really worth carrying on playing in Italy."

Boateng said he was proud his team-mates had joined him in boycotting the match and revealed the chants started before the game commenced.

"I could hear the first monkey calls after five minutes when I was on the ball," he said. "At first, I didn't think anything of it but then it happened over and over again. I went to the referee and told him that if I hear it again, then I'd quit. He tried to calm me down. When it started again in the 26th minute with the monkey calls, then I thought: 'That's it, I'm not carrying on.'"