Durant was injured when he got tangled with Heat forward Trevor Ariza early in the opening quarter. Durant appeared to sustain the injury after making contact with Ariza's knee on a drive to the basket.
The 2014 NBA MVP exited the game and was examined by the Nets' training staff before traveling to the team's locker room. Brooklyn later ruled him out for the remainder of the game.
Durant scored eight points in just over four minutes before his departure. He had yet to miss from the field.
"We're kind of used to it now," Nets head coach Steve Nash told ESPN. "We've had a lot thrown at us, different lineups. Obviously, we miss Kevin dearly when he doesn't play, but we've been able to scramble and adapt this year."
Durant, who has dealt with multiple ailments this season in his return from a major Achilles injury, returned to the Nets on April 8 after missing almost two months because of a right hamstring strain.