As Jannik Sinner confirmed his status as the undisputed king of men’s tennis, it was hard not to wonder whether we were witnessing the beginning of the end for the magnificent Italian.

World No 1 Sinner was so far ahead of his nearest rival in the ATP Rankings that he reduced defeated opponent Alexander Zverev to tears after the match, with the gap between the best in the game and the rest laid bare in a predictably one-sided contest.

Every element of Sinner’s game was better than Zverev and in truth, that story is repeated with each opponent this remarkable 23-year-old despatched in Melbourne.

He appears to be unstoppable on the court, but his biggest opponent in 2025 will not come wielding a racket and firing balls at him.

Instead, Sinner’s biggest battle is due to come in April, as the World Anti-Doping Agency appeal against the decision not to ban Sinner following last year’s failed drug tests set to be heard in April.

Sinner was found to have the anabolic steroid clostebol in his system after a doping test last Match, but was cleared of wrongdoing by the International Tennis Integrity Agency (ITIA) after they agreed with the Italian’s claims that he was not to blame for the presence of the banned substance.

That contentious verdict has been challenged by WADA, and tennis legend John McEnroe is among those expecting Sinner to be banned from the sport, with the minimum suspension of one year facing the three-time Grand Slam champion.

“A suspension is looming potentially, but he keeps it going, amazingly,” said seven-time Grand Slam king McEnroe.”I thought that (failed drg test) would affect him at the US Open, but it didn’t and he played fantastic there.

“Then they said the case was over and done with and then it crops up again. So you are thinking that’s going to get into his head, but it doesn’t. He’s able to play just as effectively, if not better.

“He’s an awesome player, there’s no doubt about it. The way he gets into the corners is unbelievable, he puts tonnes of pressure on opponents, that’s clear.”

More Tennis News

Exclusive: ITIA chief insists Jannik Sinner and Iga Swiatek did not get different treatment after failed drug tests

Jannik Sinner and Iga Swiatek failed drug tests – inside story on tennis anti-doping programme

Former world No 1 Andy Roddick also suggested Sinner’s biggest rival in the coming months will be his looming court case and there is no doubt that this story poses a huge problem for tennis.

After the ITIA supported Sinner’s claim that he was not at fault for the banned substance entering his system, the sport will have something of a credibility issue if the Court of Arbitration for Sport (CAS) supports WADA’s stance that he should have been suspended.

A ban would see Sinner miss the final three Grand Slam events in 2025 and he would also be denied the chance to defend his Australian Open title next January.

In addition, he would return to tennis in April 2026 with zero ranking points and a severely tarnished reputation, but he has insisted he is not fearful of what comes next.

“I’m not thinking about it at the moment,” said Sinner, when asked about the potential suspension that may come his way after this latest Grand Slam win in Melbourne.

“I want to enjoy this moment, to be honest. Then it’s the hearing. We know now the dates, and that’s it. I mean, I want to enjoy this one now.

“As I always say, I keep playing like this because I have a clear mind on what happened. If I knew I was guilty, I would not play like this, and that’s it.

“I still believe every time it came out in a very positive way, and I still believe it’s going to be that case. That’s it, no? At the moment I’m not thinking about this. Of course, you have your moments of certain days where you feel like I wish I would not have this problem.

“In the other way, I’m always looking forward to going on court, trying to understand. Now I also need my time off, which is also very important for my body and my mind. Then when I go again back on the court, I try to improve.”

Whatever happens at the appeal hearing in April, Sinner will always be viewed by some cynics as the guy who failed a drug test, but every doping case has nuances and the experienced ITIA team that made the decision not to ban the Italian would not have come to that conclusion unless the evidence was compelling.

While CAS decision makers could conceivably come to the same conclusion, WADA would not have pressed forward with their appeal against Sinner’s punishment unless they felt they had a strong case.

Tennis will hold its breath when Sinner and his team enter a courtroom that will serve up a much bigger challenge than his opponents at the Australian Open, with the outcome certain to have a profound impact on the player and the sport he is currently dominating.

READ NEXT: John McEnroe hints Jannik Sinner’s ban from tennis is ‘looming’ as he salutes Novak Djokovic