Last month, Sinner and the International Tennis Integrity Agency announced the news of the Italian’s positive tests and the result of his independent tribunal hearing. The tribunal was held on August 15 with the news made public on August 20. Although the two positive tests came in March, it was the first time the tennis world learned of Sinner’s anti-doping violations.

It prompted questions over whether Sinner was treated unfairly, with other players often forced to serve provisional suspensions while they await a final decision. However, official documents from the hearing revealed that Sinner appealed his two provisional bans when he was first notified of them earlier in the year, as three experts found his explanation of contamination plausible.

Federer has now claimed that questions over the inconsistencies need to be answered, though the 20-time Grand Slam champion “trusts” that Sinner didn’t “do anything”.

“It’s not something we want to see in our sport, these types of news, regardless if he did something or not, or any player did. It’s just noise that we don’t want,” Federer told Today. “I understand it’s a tricky situation.

“It’s the nightmare of every athlete and team to have these allegations and these problems because we fill out these forms all day every day. And it lives with you. Every morning when you wake up, you think, ‘Is somebody at the door coming to test me?’ So it’s really difficult.”

While the retired Swiss star understands the fears of failing a doping test, he also recognised why other players would be questioning whether Sinner received preferential treatment. He continued: “I understand the frustration of, ‘Has he been treated the same as others?’ And I think this is where it comes down to.

“I think we all trust pretty much that Jannik didn’t do anything, but the inconsistency potentially that he didn’t have to sit out while they weren’t 100 per cent sure what was going on, I think that’s the question here that needs to be answered. But look, it is what it is, and we need to trust the process as well of anyone involved here.”