Boateng, a Ghana international, 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 president Silvio Berlusconi insisting his players would always walk off the pitch if they are subjected to further racist abuse.
Boateng has, however, revealed he could be forced to turn his back on the Serie A club after telling Germany's Bild newspaper he is now considering whether to leave Italy during the current 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."
The Italian FA responded to the incident by announcing they would conduct an investigation while Boateng, who is contracted at San Siro until 2014, has received widespread support from around the football world.
The midfielder said he was "proud" that his team-mates had joined him in boycotting the the match. Boateng revealed also that the chants started before the game commenced, but after 26 minutes, he had had enough.
"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'."
Boateng said he wanted to send out a message that racism would not be tolerated.
"It's easy to just turn a blind eye; taking action is more difficult," he added.
"I was angry, sad, shocked. For things like this still to happen in 2013 is a disgrace, not just for Italy, but for football in the whole world.
"I wanted to send out a signal to the whole world that things cannot go on like this.
"We need to open our eyes. Enough is enough. Racism has no place in football."