Police Investigating Possible Fight Prior To Montee Ball Campus Attack

Law enforcement sources tell TMZ ... cops have received tips about a brawl at a UW football player's home roughly one week before Ball was jumped on campus.

According to our sources, cops have been told Ball was at the home ... and along with some of his teammates, may have participated in beating up a non-football player.

Cops were never called to the scene and no police report was ever filed.