The league is currently investigating a verbal exchange between Boston Celtics point guard Isaiah Thomas and a Washington Wizards fan during Thursday's Game 3, according to ESPN.

One of the fans at the Verizon Center posted a video of said exchange on Instagram, in which Thomas can be seen directing a profane remark at the fan in question.

“We are aware and reviewing,” NBA spokesman Tim Frank told Nik DeCosta-Klipa of Boston.com on Tuesday.

According to the fan who uploaded the video to social media, a male heckler had been “screaming all game” at Thomas to “take his toothless a** back to Boston.”

The All-Star point guard, who was sitting on the bench at the time, reportedly pointed at the fan and responded, “I will f*** you up, and you know that.”

The NBA has seen its share of altercations between players and fans, even more noticeably during the playoffs, where things get more fanatical for these supporters.

Golden State Warriors forward Draymond Green has voiced his disapproval for some fans' sense of entitlement during games, claiming that a seat in the game does not buy the right to insult people who entertain for a living — the same way a player couldn't walk into someone's shop or office and berate them.

After winning the first two games, the Celtics have lost their last two games by an average of 23 points per game, hoping to turn that around tonight during Game 5 at the TD Garden.