Jannik Sinner is about to begin the defence of his Australian Open title, but a huge cloud is hanging over the Italian ahead of his first tournament of 2025.

The world No 1 has landed in Melbourne and is the strong favourite to clinch back-to-back titles after his dominant end to last season saw him win the US Open, take the ATP Finals title and guide Italy to Davis Cup glory.

Yet the big question mark hovering around Sinner surrounds his two failed drug tests last March, with the World Anti-Doping Agency (WADA) set to launch their appeal against his punishment for that offence in a Court of Arbitration for Sport (CAS) hearing later this year.

Sinner was initially cleared by the International Tennis Integrity Agency (ITIA) of wrongdoing after an anabolic steroid was found in his system, but the WADA appeal has prolonged his agony and there is a widespread expectation that he could now serve a ban.

Now he will be hoping to convince the CAS tribunal that he did everything he could to avoid the positive doping result, with ITIA CEO Karen Moorhouse explaining to Tennis365 why the minimum punishment the Italian could receive would be a one-year suspension if the decision goes against him.

There has been an expectation that Sinner may be able to convince the tribunal that his level of punishment could be diluted even if the verdict goes against him and that a shorter suspension could be handed out.

Yet that option is not on the table, with Moorhouse confirming there are tight guidelines around a positive doping test that does not involve a contaminated product.

Women’s world No 2 Iga Swiatek completed a one-month ban last month after she posted a positive test result after taking a contaminated drug to help her sleep.

Former world No 1 Simona Halep also had her suspension reduced to nine months after successfully proving the source of her positive test was a contaminated collagen supplement.

Yet the massage cream used on Sinner by a member of his team and resulted in his positive doping test was not contaminated, as the packaging confirms it contains clostebol, the anabolic steroid that showed up in his test.

This significant contrast between the Sinner and Swiatek cases could lead to a very different outcome, with ITIA chief Moorhouse explaining the guidelines that CAS will be working with when they make their verdict.

“If you test positive for a banned substance, your starting point for a possible sanction is four years,” Moorhouse told Tennis365 in an exclusive interview.

“If you can demonstrate that it was not intentional, that reduces to two years. Then, if you can prove there was no fault, there is no sanction.

“In addition, a decision of ‘no significant fault or negligence’ could fall between a reprimand and two years. That applies to any cases around a contaminated substance.

“It’s the same rules and the same processes for every player. All cases are different and each case turns on individual facts.

“Cases can also be quite complex, so it isn’t right to look at two headlines and draw comparisons as the detail is always the key part.

“Let’s take Swiatek and Halep. The CAS tribunal found that her (Halep’s) supplement was contaminated. So just in relation to that finding, they said nine months (suspension).

“In relation to Swiatek, the contaminated product was a medication. So it was not unreasonable for a player to assume that a regulated medication would contain what it says on the ingredients.

“Therefore, the level of fault she could accept was at the lowest level as there was very little more she could have done reasonably to mitigate the risk of that product being contaminated.

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“Halep’s contamination was not a medication. It was a collagen supplement and her level of fault was found to be higher.

“The complication with the Sinner case is the positive test was not a result of a contaminated product. That is the difference between Swiatek and Halep. There is no contamination here.

“The product that the masseuse used on his finger was not contaminated. That is exactly what it said the product contained on the packaging.

“And so because it is not a contaminated product, the range for a sanction is one year to two years.”

Moorhouse’s comments banish the notion that Sinner could be handed a brief ban like Swiatek if WADA successfully proves this case should fall into the bracket of ‘no significant fault or negligence’.

The ITIA chief also confirmed her organisation will have no further role in the case that is now to be debated between WADA and the CAS tribunal.

“It is out of our control. In essence, it is the CAS tribunal that will hear that case and it is a full rehearing,” added Moorhouse.

“I know that WADA has been speaking about how the real essence of their appeal is focused on whether the player has ‘no fault or negligence’ and ‘no significant fault or negligence’.

“So the first tribunal (independent hearing convened by Sport Resolutions) found that Sinner had no fault or negligence, that he had used the utmost caution. Therefore there would be no sanction.

“My understanding from WADA’s statements is they are challenging that because they believe there was an element of fault and that the outcome should have been ‘no significant fault or negligence’.”

The date of WADA’s appeal against Sinner’s punishment following his failed drug tests has yet to be set, but it will not be in the first set of CAS appeals in 2025 that are set to take place in February.

If Sinner received a one-year suspension, it would rule him out of four Grand Slam tournaments and see his world No 1 status evaporate as he would be forced to return to the game with no ranking points.

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