World No. 1 men’s tennis player Jannik Sinner returned to competition following a three-month suspension for testing positive for a banned substance. In March 2024, Sinner tested positive during a doping test for “Clostebol,” a steroid classified as a prohibited substance. As a result, the World Anti-Doping Agency (WADA) imposed a three-month suspension, effective from February 9, 2025, to May 4, 2025.

In this newsletter, we take a closer look at the disciplinary procedures and sanctions applied in cases where an athlete tests positive for a banned substance.

1. What Constitutes an Anti-Doping Rule Violation?

The World Anti-Doping Code (WADC) strictly prohibits not only the presence of banned substances in an athlete’s doping test but also actions such as refusing or evading sample collection, or failing to be available for testing due to inaccurate whereabouts information.

One of the key principles in these cases is that an athlete’s intent, negligence, carelessness, or even use of a substance after becoming aware it was banned does not affect whether a violation has occurred. These factors are considered only when determining the length or severity of the disciplinary sanction.

Under WADC’s principle of strict liability, an athlete is held responsible for any banned substance found in their body, regardless of fault or intent.

2. The Criteria for Suspension

As described above, the strict liability principle applies when determining whether an athlete has violated WADC, meaning the athlete’s fault or intent is not considered. However, when deciding the level of the disciplinary sanction, factors such as the athlete’s intent, negligence, or carelessness are taken into account. In other words, if an athlete can prove that there was no intent, negligence, or carelessness in the violation of WADC, they may receive a lesser sanction or, in some cases, avoid any disciplinary action altogether.

To give more context, here are the specific criteria for determining the period of suspension for athletes who test positive for banned substances:

1. If the anti-doping organization can prove that the athlete acted with intent¹, the athlete will receive a four-year suspension (Article 10.2.1.2 of WADC).
2. If the anti-doping organization is unable to prove the athlete’s intent, the athlete will receive a two-year suspension (Article 10.2.2 of WADC).
3. If there is no significant fault or negligence, the athlete may receive a suspension of two years or less (Article 10.6.1.1 of WADC).
4. If the athlete can prove there was no fault or negligence on their part, they may avoid a suspension altogether (Article 10.5 of WADC).

3. Disciplinary Process

Doping tests and disciplinary procedures are overseen by individual sports organizations. In tennis, the International Tennis Integrity Agency (ITIA) conducts regular doping tests, and if an athlete tests positive for a banned substance or violates WADC, the ITIA Independent Tribunal will determine whether the athlete acted with intent or negligence and impose a disciplinary sanction, such as a suspension.

If there is a disagreement with the decision of the ITIA Independent Tribunal, the case can be appealed to the Court of Arbitration for Sport (CAS). Both the athlete subject to the disciplinary action and WADA have the right to appeal. Typically, the athlete may appeal on the grounds that the sanction is excessively harsh, while WADA may appeal if it believes the decision to waive the sanction is unjust or if the sanction imposed is too lenient.

4. Progress of the Jannik Sinner Case

Sinner tested positive for a banned substance in two doping tests - one conducted during the BNP Paribas Open (Indian Wells Masters) on March 10, 2024, and another after the tournament ended on March 18, 2024. Although the detected amount was small, WADC stipulates that “[e]xcepting those substances for which a Decision Limit is specifically identified in the Prohibited List or a Technical Document, the presence of any reported quantity of a Prohibited Substance or its Metabolites or Markers in an Athlete’s Sample shall constitute an anti-doping rule violation.” (Article 2.1.3 of WADC). Based on this, the ITIA Independent Tribunal determined that Sinner had violated WADC.

The remaining issue was whether Jannik Sinner acted with intent or negligence. Sinner argued before the ITIA Independent Tribunal that his physiotherapist used a product containing Clostebol because he had injured his hand, and that the substance unknowingly entered Sinner’s system during a massage session provided by the physiotherapist. In other words, Sinner claimed that there was no fault or negligence on his part in the process by which the banned substance entered his body, and therefore, he should not be subject to a suspension.

The ITIA Independent Tribunal accepted Jannik Sinner’s argument and, in August 2024, ruled that he should not be subject to a suspension. In response, WADA filed an appeal with the CAS on September 26, 2024, seeking to overturn this decision.

WADA reportedly sought a suspension of 1 to 2 years for Jannik Sinner in their appeal to the CAS. However, on February 15, 2025, WADA announced that they had reached an agreement with Sinner for a 3-month suspension and would withdraw their appeal. Both parties made concessions from their initial positions, and the case was resolved with an agreement that Sinner had some degree of negligence or fault in the violation related to the detection of a banned substance. 

5. Importance of Legal Response

This case highlights how, even under WADC’s strict liability principle, effective legal action can lead to a favorable result for the athlete. Jannik Sinner was initially handed a provisional suspension following the detection of a banned substance. However, by promptly presenting an explanation through his legal representative about how the substance entered his system, and showing that he was not at fault, the suspension was lifted, allowing him to complete the tournament. Moreover, despite facing a potential 4-year suspension for a serious violation, his strong legal response significantly reduced the penalty, ensuring no major disruption to his career. This case serves as a clear example of how proper legal defense can prevent excessive penalties and protect an athlete’s rights in cases of WADC violations.

Shin & Kim has a team of experts specializing in areas such as sports law and international dispute resolution, providing optimal legal counsel for complex matters such as violations of the anti-doping rules. Should you have any questions or require assistance, please feel free to contact the relevant expert.
 

¹ The Article 10. 2. 3. of WADC provides that “the term “intentional” is meant to identify those Athletes or other Persons who engage in conduct which they knew constituted an anti-doping rule violation or knew that there was a significant risk that the conduct might constitute or result in an anti-doping rule violation and manifestly disregarded that risk.”

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