Full feature behind the Athletic paywall.

From the Athletic feature, quotes excerpted via NESN:

โ€œWith the season on the line following a 128-102 Game 3 loss to the eighth-seed Heat, Grousbeck came in hot. Afterย?Grant Williams asked everyone to clear the room so the players could have some space, Grousbeck went off,โ€ The Athletic wrote.

โ€œHis message to the effect that he has been building this franchise for over 20 years and the players need toย?play with some ballsย?left the locker room stunned,โ€ The Athletic wrote.

More from Boston.com:

โ€œ[Grousbeck] was right, but we shouldnโ€™t need that,โ€ย?Blake Griffin said, according to The Athletic.ย?โ€œAs soon as we got to the locker room, we were just so frustrated.โ€

Celtics radio analyst Cedric Maxwell described the encounter as a โ€œrun-inโ€ between Celtics leadership and players.

โ€œThere were some exchanges,โ€ Maxwell said. โ€œBut, you know, I just think that Wyc and everybody else want to win and they were embarrassed.โ€