Novak Djokovic and Roger Federer have both already addressed Jannik Sinner’s doping controversy.

Jannik Sinner is once again at risk of a long ban from tennis (Image: Getty)

Novak Djokovic and Roger Federer both questioned tennis’ process and protocols after Jannik Sinner avoided a suspension despite twice testing positive for steroids. The world number one is facing the renewed threat of a long suspension after the World Anti-Doping Agency (WADA) launched an appeal against a ruling of “no fault or negligence” for two positive tests.

Sinner, who won the US Open earlier this month, twice tested positive for an anabolic steroid in March but on August 20 an independent tribunal determined he was not to blame and imposed no punishment. The tribunal accepted Sinner’s explanation that the banned substance entered his body as a result of a massage from his physio, who had used a spray containing the steroid to treat a finger cut.

But WADA has appealed to the Court of Arbitration for Sport, seeking to impose a ban of up to two years on the 23-year-old. A statement from the agency said: “It is WADA’s view that the finding of ‘no fault or negligence’ was not correct under the applicable rules. WADA is seeking a period of ineligibility of between one and two years.”

Sinner, who is playing at the China Open, says he has been left “disappointed and surprised” by WADA’s appeal. But the initial verdict, which allowed Sinner to carry on playing, led to suggestions the Italian had been given preferential treatment due to his lofty standing in tennis.

Federer can understand why fellow players and fans would jump to that conclusion. Speaking on the Today Show earlier this month, the Swiss legend said: “I understand the frustration of: Has he been treated the same as others? And I think this is where it comes down to. We all trust pretty much at the end, he didn’t do anything.

“But the inconsistency, potentially, that he didn’t have to sit out while they were not 100% sure what was going on. I think that’s the question here that needs to be answered.”

Djokovic raised similar concerns last month, saying via AP: “I understand the frustration of the players is there, because of a lack of consistency. As I understood, his case was cleared the moment basically it was announced.”

Roger Federer and Novak Djokovic have both questioned Jannik Sinner’s treatment (Image: Getty)

The 24-time Grand Slam winner added: “We see a lack of standardised and clear protocols. I can understand the sentiments of a lot of players that are questioning whether they are treated the same.

“Many players have had similar or pretty much the same cases, where they haven’t had the same outcome. And now the question is whether it is a case of the funds, whether a player can afford to pay a significant amount of money for a law firm that would then more efficiently represent his or her case.”

However, Rafael Nadal disagrees with his fellow icons and doesn’t believe Sinner has received preferential treatment. The Spaniard told Spanish talk show El Hormiguero: “If he hasn’t been sanctioned, it’s because the judge has clearly seen that he hasn’t doped. I don’t think they have judged him as innocent simply because he is the world number one.”

Sinner gave his reaction to WADA’s appeal after beating Roman Safiullin in three sets in Beijing. He said via China Open Press: “I’m very disappointed and also surprised because we had three hearings. All three hearings came out very positively for me.”

On news of the appeal emerging while he was playing, the Italian added: “Well, we cannot control everything, no? Obviously, I’m very disappointed and also surprised of this appeal, to be honest, because we had three hearings.

“All three hearings came out very positively for me. You know, I was not expecting it. I knew it a couple of days ago, that they were going to appeal, that today it’s going to go official, so… But yeah, it’s surprise.

“We always talk about the same thing. Maybe they just want to make sure that everything is in the right position. Yeah, I’m just surprised that they appealed.”