American Frances Tiafoe might be in some serious trouble after insulting umpire Jimmy Pinoargote at the end of his third-round defeat to Roman Safiullin at the Shanghai Masters. The World No. 17 issued an apology on his Instagram account, but it might not be enough to avoid a punishment from tennis officials.

“I really apologize for the way I acted tonight. That is not who I am and not how I ever want to treat people. I let my frustration in the heat of the moment get the best of me and I’m extremely disappointed with how I handled the situation. That’s not acceptable behavior and I want to apologize to the umpire, the tournament, and the fans. I’ll be better for yall,” he wrote on his Instagram story.

After losing the match 5-7, 7-5, 7-6(5), Tiafoe calmly congratulated Russia’s Safiullin at the net, before shouting, “F* you, man. F* you. Seriously, man. F*** you. You fed me” at Pinoargote as he walked towards the umpire. After a pause, Tiafoe added: “You fed the match up. Great fing job. F you.”

He continued to shout, telling the umpire: “You’re going to be on the fing blacklist for my matches. Never again. Literally had it out for me today. Fing insane.” He was mad after Pinoargote gave him a time violation when he was serving at 5-5 in the final set tiebreak at the tournament in China on Tuesday.

Frances Tiafoe of United States (Zhe Ji/Getty Images)

After a lengthy rally, which Tiafoe won, he walked up to the line before throwing the ball into the air, his serving arm by his side. “I’m not buying it, it’s a second serve,” said the umpire. It was Tiafoe’s third time violation, so he lost his first serve. Tiafoe then lost that point, and the next one, to lose the match 5-7, 7-5, 7-6(5).

What does the ATP’s rulebook say?

According to the ATP’s 2024 rulebook: “Players shall not at any time directly or indirectly verbally abuse an official, opponent, sponsor, spectator or any other person within the precincts of the tournament site. Verbal abuse is defined as any statement about an official, opponent, sponsor, spectator or any other person that implies dishonesty or is derogatory, insulting or otherwise abusive.”

The violation of this rule “shall subject a player to a fine up to $60,000 (£45,767) for ATP Tour Masters 1000 tournaments for each violation.” However, if the code of conduct violation is considered “particularly injurious to the success of a tournament, or are singularly egregious,” an investigation takes place to determine whether there’s a major offense.