Boca Raton police said they were called to the Life Time Gym by a man who said Incognito threw a tennis ball and dumbbell at him.
TMZ said Incognito was "rambling about the government and screaming at the man to 'get off my (expletive) playground.'" That's when the police were called. Incognito used the social-media platform in April to announce his retirement, and he followed that up by telling a Buffalo newspaper, "My liver and kidneys are shutting down".
Just two days after the Bills released him, the offensive lineman is in a mental health facility.
O'Brien told The Associated Press on Thursday that Incognito also ripped apart a boxing mannequin and slammed his knee into its head, and feared Incognito might do the same to him. Incognito told officers he had taken "Shroom Tech", an over-the-counter supplement.
According to the report, Incognito told a Lifetime Fitness employee "don't f--g cross the line", after Incognito was allegedly "acting erratically, throwing things at staff".
"He started yelling at me like he was going to kick my ass and beat the [expletive] out of the equipment over here", O'Brien said in the 911 call regarding the incident obtained by the Herald. He told the dispatcher Incognito, who was dressed in shorts and no shirt, was trying to hit him as they talked.
Officers said when they tried to tell Incognito they were concerned he would hurt someone or himself; he asked a woman at the gym to call the Federal Bureau of Investigation.
Incognito was not arrested and he hasn't been charged with any crimes. Incognito was among the players identified for targeting teammate Jonathan Martin in the Miami Dolphins' bullying scandal during the 2013 season. The Bills released him from their reserved/retired list on Monday, leaving open the possibility he could sign with another team.
Just a month beforehand, Incognito and his team had agreed to a renegotiated contract.