Jabari Bird has been arrested after allegedly assaulting, strangling and kidnapping an unidentified person in a domestic incident.
Bird is being "guarded by the Boston police at a local hospital" for evaluation.
The Celtics acknowledged in a statement that they were "aware of the incident" involving Bird and are "taking it very seriously."
Bird was the 56th overall pick in the 2017 draft and spent the 17-18 season on a two-way contract. Bird was signed to the Celtics' active roster this summer.