A couple of players have spoken up in support of Zverev’s former girlfriend Olga Sharypova. But apart from Nicole Gibbs and Daria Gavrilova – the Russian-turned-Australian who said “I think you have to believe a woman” –the sport has done its best to brush Sharypova’s powerful allegations out of sight.

Sharypova’s claims are unproven, and are likely to remain so, unless she takes legal action. Even so, if tennis was a logical and joined-up business, it would have launched its own investigation by now. That’s what would happen in American sports leagues such as the NBA, where anyone accused of domestic violence is suspended on full pay, pending an investigation.

Tennis, as a sport, has enough resources to do the same. Unfortunately, those resources are spread thinly and unequally across nine different stakeholders.

In any rational world, the Association of Tennis Professionals could call upon the services of the Tennis Integrity Unit, and the 16 investigators – mostly former policemen and women – who work there. In our messy reality, however, the TIU is part of a different silo, focusing on betting fraud and answering mainly to the International Tennis Federation. The ATP has no investigators of its own.

Zverev finished his season with a straight-sets loss to Novak Djokovic on Friday. He has denied all the allegations in the tersest of fashions-such is his right. But unless there are dramatic developments, the same debate will recur at the Australian Open (Covid-19 allowing) in January.

Reporters will raise the issue with Zverev again, knowing that his answer is unlikely to have changed, but feeling that it is inappropriate to brush such serious matters aside. He will deny the charges again. And the same miserable, nauseous feeling will follow his progress through the tournament.

Even if Zverev is completely innocent, the unresolved nature of the case is bringing the game into disrepute. Which is why the authorities should be trying to glean more information about Sharypova’s claims. Remember the panic created in the tennis world by the 2016 BBC/Buzzfeed investigation into match-fixing? In response, the ATP’s then chief executive Chris Kermode dragged his fellow tennis bigwigs into a room at Melbourne Park for a press conference.

Admittedly, the result was less than satisfactory: an Independent Review Panel which spent perhaps £25 million in producing a 115-page statement of the obvious. But at least tennis showed that it cared about defending its integrity against match-fixers. Now it needs to show that it cares about domestic abuse as well.

There are technical challenges here, in that tennis players are individual contractors. Unlike team sportsmen, they do not sign employment contracts, nor collective bargaining agreements that can be used for disciplinary purposes when they transgress.

But the seriousness of these allegations requires the formulation of an official domestic-abuse policy, at the very least. And the TIU – which will expand to take on anti-doping responsibilities in a year’s time – should also be mobilised as a potential arbiter in those awkward cases where no civil or criminal charges have been brought.

Doping, match-fixing and abuse: these are the three horsemen of modern sport. They might as well be brought under one roof.