Boston Celtics center Robert Williams III (44) dunks the ball over Miami Heat guards Avery Bradley (11) and Andre Iguodala (28) during the second half of an NBA basketball game, Wednesday, Jan. 6, 2021, in Miami.
That process would not have been completed in time for the 7 p.m. game, so the league called it off.
Boston was preparing to play the game with eight available players; the Celtics have 17 on their roster, seven were out due to the COVID-19 protocols and two more with injuries.
The other was Dec. 23, an Oklahoma City at Houston game where the Rockets did not have the required eight players available.
They were in Miami for a game on Wednesday, and Bradley played in that game for the Heat.