Green made a throat-slash and trigger gesture after hitting a shot. Last season, teammate Dwyane Wade was fined $15,000 for making an obscene gesture toward a fan in a game against the Charlotte Hornets.
Green scored 28 points in the game as the Heat went on to win 110-105 over the Wizards.
Green, 29, played the last two seasons with the Phoenix Suns. Miami will be the eighth NBA team he has played for over his 10-year professional career, which also included a two-year stint in Russia. He signed a one-year contract with Miami in July.
Watch Green's move against the Wizards below:
- Christopher Chavez