Jannik Sinner has revealed he has learned the identity of his real “friends” during his ongoing doping case.

But the world No.1 has insisted he was able to keep playing and winning this season because he knew he was innocent.

The Italian twice tested positive for banned substance clostebol in March but an independent panel concluded he bore “no fault or negligence” on a judgement just before the US Open.

The Australian Open champion triumphed in New York under incredible pressure to claim his second Grand Slam of the year – and he won his seventh title in Shanghai earlier this month.

Yet the case is not over after the World Anti-Doping Agency (WADA) launched an appeal to the Court of Arbitration for Sport (CAS) seeking a ban.

An insight into Sinner’s mentality before the case became public will now be shown in an interview with Sky Sport Uno in Itay which was recorded last month between his US Open win and the WADA appeal.

Speaking on September 18, the Italian revealed: “I can say that it was difficult because I couldn’t open up to many people, it was a delicate and difficult period. At the beginning everything was complicated, I didn’t know how to behave, I didn’t know what was coming out, what would happen with the team.

“I’m usually always in control but in this case it was easy to lose it. After a few weeks I woke up and told myself that I hadn’t done anything wrong, I didn’t know anything, for me it had already happened.

“The most difficult moment was when the news came out, in a delicate moment, before a Grand Slam. We arrived at the courts and everyone had all cameras ready, I was looking at the other players to understand what they really thought.

“I asked myself a lot of questions – it was difficult to prepare for a Grand Slam like this. I am convinced that nothing happens by chance and it has allowed me to understand who was my friend and who wasn’t.

“I realised that there are a lot of players who I didn’t think were friends and others who ultimately are not. It was difficult when nothing had happened yet, they saw me with my head down and asked me: ‘Why are you like this if you won?’. And what did I answer there? I said everything was fine.”

British No.1 Jack Draper came out strongly in support of his friend Sinner before the US Open and stated: “He’s one of the nicest, most genuine, kind, professional guys that I’ve been around on the tour.”

Novak Djokovic called for “change” in the rules after the controversy surrounding Sinner’s doping case while Nick Kyrgios branded the process as “ridiculous”.

Sinner suffered from sickness while losing at Wimbledon to Daniil Medvedev but insisted he could never have won in New York if he had been guilty.

“There were matches that I didn’t sleep the night before, like the one at Wimbledon against Medvedev,” he said. “It’s normal for you to feel bad the next morning. I’ve tried to put away a lot of things in this period, I have to thank my team that was close to me, I felt protected. That’s why I dedicate the tournaments to them, without them I couldn’t overcome it. Was I sure I was right? If I had known I was guilty I would never have played like that.”