Jannik Sinner could not help but crack a wry smile when he faced the media before the US Open last year in the aftermath of his anti-doping case, one of the most high-profile in the history of tennis.
Sinner, the best player in the world, had been attempting to emphasise just how low the concentration of the banned substance clostebol had been in his urine sample, and therefore how irrelevant it was to his performances on the court.
