Oklahoma City Thunder star Russell Westbrook said he was verbally provoked before directing a profanity-laced tirade at a fan during the Thunder's 98-89 win over the Utah Jazz on Monday in Salt Lake City.
A reporter from the Deseret News tweeted a video of Westbrook's comments to the fan.
"I promise you," Westbrook said to the fan. "You think I'm playing. I swear to God. I swear to God. I'll [expletive deleted] you up; you and your wife. I'll [expletive deleted] you up."
When another person appears to intervene, Westbrook says, "No, [expletive deleted] that!
Then apparently addressing the fan again, he said, "I promise you, everything I love. Everything I love, I promise you."
After the game, Westbrook gave his explanation: "How it started was, a young man and his wife in the stands told me 'to get down on my knees like you used to'.
"To me, that's just completely disrespectful, to me, I think it's racial, and I think it's inappropriate and insensitive.
"Then there are people that come to the game to say mean, disrespectful things about me, my family.
"And if I had to do it again, I would say the same exact thing, because I truly will stand up for myself, for my family, for my kids, for my wife, for my mom, for my dad every single time. I expect anybody else to do the same.
"As for beating up his wife, I've never put my hand on a woman. I never will. Never been in any domestic violence before. But once he said the comment, and his wife repeated the same thing as well. That's kind of how that started."
Salt Lake City NBC 5 identified the male fan involved in the exchange as Shane Keisel, a Jazz fan, and spoke with him.
Keisel said he was playfully bantering with Westbrook before Westbrook started cursing at him.
"I never said a single swear word to him, not one," Keisel told the TV station. "Initially, I was like, 'Oh, I'm talking with Westbrook, the guy is one of the greats. He's also classless.
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"He can threaten me all he wants. I was the one talking to him, but don't threaten a woman. She's 5ft tall and 110 pounds, man. [She] never said a word to him."
Five fans at the game were issued "warning cards" citing the NBA's code of conduct after the incident, the Deseret News reported.
The NBA later issued a statement: "We are continuing to investigate the unfortunate exchange at tonight's game between Russell Westbrook and fans.
Multiple warning cards were issued by arena security. Players and fans have a shared responsibility to create a safe and respectful environment. If it is determined that any fans violated the NBA Code of Conduct, appropriate action will be taken."
Westbrook had another testy interaction with Jazz fans in last year's playoffs when he slapped a fan's cell phone as he walked off the court.
Last month, a young kid sitting courtside in Denver nudged Westbrook after he stepped out of bounds. In that instance, Westbrook stopped and had a calm conversation with the fan and his dad.