Cubs KO Victim Was Arrested for Assault & Harassment

The Chicago Cubs fan who was knocked out cold after Game 7 of the World Series was enough of a hothead recently to get arrested twice ... TMZ Sports has learned.

Alan Anderson was busted by Chicago cops Sept. 10th for the crimes of phone harassment and assault. Law enforcement sources say the alleged victim is Anderson's ex-girlfriend. According to docs, he allegedly called her 160 times and left a voicemail saying, "I am coming for you, I'm bringing brass knuckles for you."

He was arrested at a bar in Chicago. The case is being handled by the domestic violence unit in the prosecutor's office.

He was also busted in March for another misdemeanor case of harassing someone by phone.

Anderson did not want to discuss his arrests -- he has an upcoming court date -- but he did strongly deny he was talking smack with the Indians fan who knocked him out Wednesday night.

He admits he was celebrating loudly, but not in anyone's face, when the Indians fan approached and told him to shut up. He says they argued for a bit, and then the guy punched him out of nowhere. Anderson says he was calmly pleading his case when he got hit, and did not dare him to swing ... as witnesses have claimed.

As we told you, Cleveland PD is investigating.