Jannik Sinner celebrated winning his maiden US Open championship on Sunday in New York.
In Montreal, World Anti-Doping Agency officials are now deciding whether to file a formal appeal of Sinner's exoneration of doping charges by a tribunal last month.
More: Jannik Sinner Tests Positive for Banned Steroid
WADA officials told the Associated Press two organizations, WADA and Nado Italia, Italy’s anti-doping agency, are the only two associations that could appeal the decision by an independent tribunal to clear Sinner.
While Nado Italia has yet to appeal the ruling in Sinner's case, WADA has three more weeks to file an appeal with the Court of Arbitration for Sport in Lausanne, Switzerland.
"While the doping rules state that any other party with a right to appeal — such as Nado Italia — has 21 days to do so, WADA then gets another 21 days on top of that before its own window closes," the Associated Press reports.
Last March, Sinner twice tested positive for the banned steroid clostebol in "low levels" the International Tennis Integrity Agency announced in August days before the start of the US Open.
World No. 1 Sinner was not suspended because an indepent tribunal ruled he was at "no fault" for the steroid contamination in his system.
"The International Tennis Integrity Agency (ITIA) confirms that an independent tribunal convened by Sport Resolutions has ruled that Italian tennis player Jannik Sinner bears No Fault or Negligence for two Anti-Doping Rule Violations under the Tennis Anti-Doping Programme (TADP), having twice tested positive for the prohibited substance clostebol in March 2024," the ITIA announced in a statement on August 20th.
Two-time Grand Slam champion Sinner adamantly denies doping or cheating.
Sinner provided a urine sample at Indian Wells on March 10, 2024, which contained the presence of a metabolite of clostebol "at low levels," the ITIA announced.
A further sample, conducted out of competition eight days later, also tested positive for the same metabolite.
Clostebol is a synthetic steroid "with anabolic effects that is frequently used in sports to increase physical performance," according to Oxford Academic.
So why was Sinner still playing after two positive tests?
The ITIA said after each positive test, a provisional suspension was applied.
"On both occasions, Sinner successfully appealed the provisional suspension and so has been able to continue playing," the ITIA said.
At the US Open, Sinner said he was contaminated by the banned substance, clostebol, through contact with his physiotherapist.
Conceding he was “worried” he could be banned, Sinner said he was also confident he would be cleared because he believes the minute trace amounts of clostebol in his system reinforce his claim of inadvertent contamination.
“Of course I was worried, because it was the first time for me, you know, and hopefully the last time that I am in this situation, position,” Sinner said. “There also a different part we have to see is the amount I had in my body, which is 0.000000001, so there are a lot of zeroes before coming up a 1.
"So I was worried, of course, because I'm always the player who was working very, very carefully in this. I believe I'm a fair player on and off the court.”
The top-seeded Sinner confirmed coach Darren Cahill’s statement that both his physiotherapist, Giacomo Naldi, and his trainer Umberto Ferrara, have been dropped from his team because he no longer had “confidence” in the pair following his failed doping test. Cahill and co-coach Simone Vagnozzi were with Sinner in New York.
“I want to start with that they have been a huge part for my career. We worked together for two years,” Sinner said. “We made an incredible job, bringing a lot of success and then having a great team behind me. “Now, because of these mistakes, I'm not feeling that confident to continue with them.
"The only thing I just need right now, just some clean air. You know, I was struggling a lot in the last months. Now I was waiting for the result, and now I just need some clean air.”