In a viral video of the incident, a fan sitting courtside could be heard heckling Irving, who responded with obscene language.
Irving has appeared in just five games for the Nets this season. He has averaged 22 points, 5.4 assists and five rebounds over 34.4 minutes per game.
The 29-year-old Irving scored 30 points across 38 minutes during the Nets' 119-118 victory over the Washington Wizards on Wednesday night.
Irving remains unvaccinated against COVID-19, meaning he can't play in home games because of a mandate in New York City. After Irving stayed away from the team for about three months, the Nets reversed course last month and allowed him to take part in road contests.
The Nets' game against the Wizards on Wednesday marked the two-week anniversary of his return to the franchise.