You can just imagine how Jack Draper’s maiden Grand Slam semi-final would be billed if Eddie Hearn were promoting him. “Saint versus Sinner.” There would be billboards along Fifth Avenue, adversarial press conferences, and a start time carefully calibrated to give the British audience a pay-per-view feast once the pubs had kicked out.

Naturally, few besides his nearest and dearest know quite how saintly Draper is. But this is one New York duel where the subplot sells itself. In one corner, you have the clean-cut Home Counties boy fond of posing for Vogue in his designer knitwear. And in the other, there is Jannik Sinner, the world No 1 who left the tennis world reeling last month when it was revealed that he had twice tested positive for a banned anabolic steroid, and who escaped suspension after his lawyers successfully argued the substance entered his system via a physiotherapist’s massage.

At face value, Sinner is hardly the most persuasive villain. There is no wrong-side-of-the-tracks edginess to the Italian: he grew up in Sexten, a town of picture-postcard perfection in the Dolomites, and the most striking detail of his youth is that he won a national junior ski title. The “Carota Boys” who follow him on tour are not exactly mischief-makers either, besides their penchant for dressing up as giant carrots in honour of their idol’s red hair. And yet in the context of Sinner’s recent investigation by the International Tennis Integrity Agency (ITIA), not to mention the opaque way it has been handled, his match-up against Draper acquires a piquancy all its own.

Tennis world frustrated by handling of Sinner saga

Even Roger Federer, normally diplomatic to a fault, has weighed-in this week on the two-tier justice system that allowed Sinner to carry on playing throughout an anti-doping inquiry while players without the access to expensive legal teams had their livelihoods put on hold. “It’s not something we want to see in our sport, these types of news, regardless if he did something or not,” the 20-time major champion said. “Or if any player did. It’s just noise that we don’t want.

“I understand the frustration: Has he been treated the same as others? And I think this is what it comes down to. We all trust pretty much that in the end, he didn’t do anything. But the inconsistency, potentially, is that he didn’t have to sit out while they were not 100 per cent sure what was going on. I think that’s the question here that needs to be answered.”

It is vanishingly rare for Federer to speak out like this on any subject. But even the model of Swiss urbanity feels uncomfortable at the impression that Sinner has received preferential treatment. Why was Sinner able to sail serenely on, while Britain’s Tara Moore had her reputation besmirched for 19 months before the ITIA eventually agreed with her claim that her positive tests for boldenone and nandrolone were due to her having eaten the meat of steroid-dosed cattle?

Stefano Battaglino, one of Sinner’s compatriots, also suffered a starkly different fate to the Australian Open champion when he found himself in a similar situation two years ago. He, like Sinner, tested positive for clostebol. He, like Sinner, suggested that the cream applied by his masseur must have contained the prohibited drug. But without the financial resources to mount a robust defence, he was left high and dry, with his physio going to ground and the authorities punishing him with an effectively career-ending four-year ban.

It all adds up to an image that Sinner, despite being cleared, escaped relatively lightly compared to his less prominent peers. There has been a striking lack of unconditional endorsement during the US Open: while Novak Djokovic called for “clear protocols” and a “standardised” approach to doping cases, Carlos Alcaraz said: “It’s a really difficult moment for him. It’s complicated.”