The NBA fined Isaiah Thomas $25,000 yesterday for "directing inappropriate language toward a fan" during Game 3 in Washington.
The fine was announced by the NBA in a news release.
A spectator sitting behind the Celtics bench filmed the exchange between Thomas and the fan and posted it on Instagram.
"Things got a little heated last night at the game from the bench as well," said the caption from Instagram user "thesportytraveler." "All 5'7 (5'9 my ass) of Isaiah Thomas told this disrespectful fan, I will f*** you up and you know that.....lol"
Check out the clip below.