Police Commissioner William Bratton says he is "very concerned" with the performance of officers involved in the arrest of a postal worker who was out driving a mail truck in Brooklyn.

Bratton says the NYPD's internal affairs bureau is investigating the arrest of 27-year-old Glen Grays on March 17 in Crown Heights.

Grays says he was delivering mail in his mail truck when he was almost struck by an unmarked police car.

He says he yelled at the plainclothes officers and a lieutenant before they got out and asked for identification.

Cellphone video appears to show the officers shouting, 'Stop resisting,' and Grays saying he is not.

Grays was handcuffed and taken to a local precinct, where he was issued a summons for disorderly conduct.

Speaking to reporters Tuesday, Bratton said he has "strong concerns about the charge against the individual" based on the videos he reviewed.

He also said the lieutenant and three officers were assigned to a conditions unit and that conditions units are "not to work in plainclothes."

"So in sum and in substance, I'm very concerned about the performance of the officers, about the leadership of the lieutenant involved and about the processing of the arrest at the precinct stationhouse," Bratton said.

Bratton added that he was concerned that the worker's postal truck was left unsecured and double-parked on "a major thoroughfare in the city of New York."

Last week, Brooklyn Borough President Eric Adams said Grays' federal employee civil rights were violated.