The Minnesota Vikings informed Everson Griffen and his agent he would need to undergo a mental health evaluation before being allowed back with the team.
Team management sent Griffen and his agent the letter on Thursday, two days before an alleged incident involving Griffen at a Minneapolis hotel.
According to the incident report, Pico told police that Griffen had been "explosive, screaming and yelling" at the team facility and that he had been struggling in recent weeks.
Griffen is being evaluated at a Minneapolis-area hospital, according to the incident report. A league source told ESPN's Josina Anderson that Griffen is "getting assistance on personal matters" and that the league is "comfortable he has a good support system around him."
Griffen reportedly told an officer about people trying to kill him. Griffen also jumped out of the ambulance, saying he was in fear of someone shooting him, before ultimately being calmed and taken to the hospital.