Following the Boston Celtics' Game 4 loss to the Wizards, which brought the series back to even at 2-2, Isaiah Thomas voiced his frustration with the refs and the lack of calls he received.

Thomas told reporters during his post-game press conference, via ESPN,

"But I have to put it on the refs to call it. So I'm going to keep attacking and keep being myself no matter if they're calling it or not. But it does get a little frustrating when you continue to play the same way and there's nothing being called."

But the lack of trips to the free throw line wasn't the only thing that got under Isaiah's skin throughout Game 4.

During Boston's loss, Isaiah Thomas briefly got into it with a heckling fan. Although you can't hear exactly what the fan is saying to Thomas, you can clearly see the 5'9 point guard call out to the fan and say, "I will fuck you up. And you know that. Just make sure after, you come right here and say it."

Check out the clip below.