The cop who says he was attacked by Toronto Raptors president Masai Ujiri after Game 6 of the NBA Finals now claims he suffered a concussion during the incident ... and he's threatening to sue.
"He has a serious concussion; a templar mandibular joint injury, which is a serious jaw injury,” the officer's attorney David Mastagni told KPIX 5.
The incident went down Friday in the moments after the Raptors beat the Golden State Warriors at Oracle Arena in Oakland ... the cop says Ujiri got violent over a dispute over credentials.