On Tuesday night, Jack Sock was angry. Very angry. He had just lost in the Wimbledon first round from two sets up against the Italian, Matteo Berrettini, and he was in no mood to hide his displeasure.

Where 99 per cent of tennis players would have shaken their opponent’s hand and then spouted platitudes afterwards, Sock reacted as Sock does.

He told Berrettini: “Your coach is a piece of s---, by the way.” As for the post-match platitudes, Sock did not even speak to the press. Instead he ignored his media obligations and left the All England Club.

For the Berrettini insult, Sock was fined $5,000 (£3,785) for unsportsmanlike conduct. For the media blackout, he will avoid the usual fine because he claims he was not informed of the requests. Step aside Nick Kyrgios, this is the real tennis bad boy.

A 25-year-old from Nebraska, Sock was once the great hope of American tennis. As recently as November, he rose to a career-high ranking of No 8 after winning the Paris Masters and reaching the semi-finals of the ATP World Tour Finals. In 2014 he won the Wimbledon men’s doubles title with Vasek Pospisil.