Jannik Sinner took his first steps on the clay courts of the Madrid Open on Saturday 20 April. By that time, although the rankings did not yet reflect it, Sinner was undeniably the best player in the world. He had won his first grand slam title at the Australian Open in January before embarking on a spectacular, consistent run. His pre‑tournament interviews in the subsequent days were dominated by his budding rivalry with Carlos Alcaraz, a match-up that many believe will define the next generation of men’s tennis.

What only Sinner, his team and the anti-doping authorities knew then, however, was that until the day of his first training session in Madrid, he had been banned from entering the tournament grounds or any other official grounds or courts because of the automatic provisional suspension he had received in the aftermath of him twice testing positive for the banned substance clostebol.

None of that information was made public until this week when the International Tennis Integrity Agency (ITIA) and Sinner’s team revealed jointly that the 23-year-old had been found to bear no fault or negligence for the presence of clostebol in two of his anti-doping test samples taken in March. It is significant enough that the No 1 men’s tennis player has twice tested positive for a banned substance, but it is an even more remarkable situation due to the silence that had led up to this revelation.

Most anti-doping cases end up with a player receiving notification of a failed test and then being provisionally suspended until an independent tribunal has ruled on the case at the end of a lengthy, public process.

In Sinner’s case, he was notified for his first positive test on 4 April, just four days after he won the Miami Open. Sinner immediately filed an urgent application to lift the provisional suspension and his request to do so was granted a day later, meaning the ban was not publicly announced.

Sinner received notification of the second positive test on 17 April and the immediate provisional suspension was lifted on 20 April. With his ban occurring at the beginning of the busiest period of the season, Sinner was extremely fortunate that neither of those ­short‑lived provisional bans fell on a tournament week.

While it is rare for provisional bans to be lifted, they can be appealed at an urgent hearing if an athlete is arguing either contamination or if it involves a substance of abuse, with the hearing deciding if a player is likely to be found to have no fault at the end of the process.

A notable attempt to overturn a provisional ban came when Dayana Yastremska of Ukraine was provisionally suspended in January 2021 after testing positive for mesterolone.

Yastremska travelled to the Australian Open, which was being played under severe Covid-19 restrictions, while still awaiting the results of her application to lift the suspension but the request and subsequent appeal to the court of arbitration for sport were both dismissed. Yastremska was eventually found to bear no fault or negligence by an independent tribunal five months later.

Among the numerous positive cases for clostebol among Italian athletes, the recent case of Marco Bortolotti, a 33‑year‑old with a career-high ranking of 355, bears some similarities to Sinner. Bortolotti was notified of the test on 30 January 2024 after testing positive for clostebol last October. He immediately provided an explanation, which the ITIA accepted after seeking scientific advice and it took just eight days for the agency to conclude on 7 February that he bore no fault or negligence. The nature of Bortolotti’s explanation has been redacted in the ITIA’s final decision.

With Sinner being permitted to compete, two separate storylines have been playing out over the last five months. On one hand, Sinner has had a breakout season that has seen him rise to No 1 in the ATP Rankings and consolidate his first grand slam triumph in Melbourne with an extremely consistent season.

At the same time, this case has continued to progress in private and it has intersected with numerous significant events. During his run to the French Open semi-finals, for example, Sinner’s defence team responded to the ITIA’s official notice of adverse analytical findings and he won his third-round match against Pavel Kotov a day after he was formally charged with an anti-doping rule violation. Sinner’s independent tribunal was held the day after his first-round win at the Cincinnati Open last week. For some, the lack of transparency throughout his case has been troubling.

Darren Cahill, Sinner’s coach, alongside Simeone Vagnozzi, said in an interview with ESPN that Sinner has been worn down by the case. “If you are a Jannik fan, you would have seen a big change in his body language, physicality on the court, his excitement to be on the court – he’s struggled and I think it’s worn him down physically and mentally,” he said. “He got tonsillitis, which is the reason why he missed the Olympics.

“I just want to stress that he’s maybe the most professional young man that I have ever had the chance to work with. He would never ever intentionally do anything, and he’s in a situation that is incredibly unfortunate.”

Sinner has been a popular player on the tour but since the announcement, some players have publicly taken significant issue with this case and what they perceive as favouritism towards the No 1 player, particularly considering the lengthy provisional bans that other players have been subjected to before a resolution was found in their cases. It is a sentiment that was summed up by the world No 54 Roberto Carballés Baena in a comment on his Instagram story: “One more time. Different rules for different players.”