Sinner and Świątek: Wimbledon Glory Tainted By Doping Allegations?
This year’s Wimbledon singles titles were claimed by Iga Świątek and Jannik Sinner, both securing their first victories at the All England Club. Świątek delivered a ruthless double bagel against Amanda Anisimova, winning 6-0, 6-0 without conceding a single game, while Sinner earned revenge over Carlos Alcaraz following their infamous showdown at Roland Garros in June. However, beyond their maiden Wimbledon successes, Świątek and Sinner share a more controversial connection. Both players have served suspensions within the past twelve months following anti-doping violations, prompting scrutiny of how transparently tennis handles disciplinary matters.
This article explores the details of each case, the sanctions imposed, the reactions from within the sport, and the broader implications for fairness, credibility and transparency in professional tennis.
Jannik Sinner
What triggered the investigation?
On 10 March 2024, during the BNP Paribas Open in Indian Wells, and again in an out-of-competition test on 18 March, Jannik Sinner tested positive for trace amounts of clostebol, a prohibited anabolic agent.
What is clostebol, and why is it prohibited?
Clostebol is a synthetic anabolic steroid derived from testosterone. Though legally available in Italian pharmacies and found in topical sprays like Trofodermin, it is prohibited under S1.1 of the World Anti Doping Agency’s (WADA) Prohibited List for its muscle-building and recovery-enhancing effects. Its presence in an athlete’s system constitutes a violation, regardless of quantity, unless a Therapeutic Use Exemption (TUE) is granted. Sinner did not hold a TUE. Both of his samples were reported to contain very low levels of the substance, measuring 121 and 122 picograms per millilitre, respectively.
What explanation did Sinner provide?
Sinner attributed the positive tests results to accidental transdermal contamination. His physiotherapist, Giacomo Naldi, treated a cut to his finger using an over-the-counter healing spray containing clostebol, which had been supplied by Sinner’s fitness coach Umberto Ferrara, who has recently returned to his team. Over the next nine days, Naldi continued treating Sinner’s body without wearing gloves. Sinner’s team argued that during this period, extremely small amounts of clostebol were transferred from Naldi’s hands onto Sinner’s skin and gradually absorbed into his bloodstream. This, they claimed, accounted for the presence of clostebol metabolites in both urine samples.
Tribunal ruling, WADA appeal, and negotiated resolution
On 4 April, Sinner was provisionally suspended from tennis for breaching Articles 2.1 and 2.2 of the Tennis Anti Doping Programme (TADP), which impose a regime of strict liability. Under these provisions, an Anti Doping Rule Violation (ADRV) is established simply by the presence of a prohibited substance in an athlete’s sample, irrespective of intent, fault, negligence or knowledge. Sinner appealed to the International Tennis Integrity Agency (ITIA), the global body responsible for anti-doping in tennis. He was permitted to continue playing while proceedings were ongoing. On 15 August, an independent tribunal appointed by the ITIA and administered by Sports Resolutions cleared Sinner of wrongdoing. The panel, chaired by David Sharpe KC, accepted the explanation of unintentional contamination and dismissed the doping charge. The appeal had been submitted on the same day Sinner received formal notice of his initial adverse analytical finding, accompanied by a laboratory report and written submissions from his team.
At the hearing, three scientific experts endorsed the claim that the positive test stemmed from unintentional transdermal absorption during treatment by his physiotherapist. Investigators conducted ten interviews and consulted three specialists in the field of anti-doping science, including Professor David Cowan of King’s College London. All three experts found Sinner’s explanation scientifically credible. Professor Cowan noted that even if clostebol had been intentionally applied, the quantities detected were so minimal that they would have produced no meaningful performance enhancing effect.
The ITIA ultimately concluded that Sinner bore no fault or negligence under Article 10.5 of the TADP, citing the fact that the substance was introduced by his physiotherapist without his knowledge. According to Appendix One of the TADP, a finding of ‘no fault or negligence’ requires the athlete to prove that they neither knew nor could reasonably have suspected the presence or use of the prohibited substance, even with the utmost caution. Based on this, Sinner was fully exonerated and escaped a doping ban. However, as per Article 10.10 TADP, Sinner had to forfeit the $325,000 in prize money and 400 ranking points he earned by getting to the semi-finals at Indian Wells.
On 26 September, the World Anti Doping Agency appealed the ruling. Relying on Article 13.2, WADA challenged the ITIA tribunal’s application of the ‘no fault’ standard, maintaining that the decision was inconsistent with established case law. In December, WADA Director General Olivier Niggli reiterated that the agency did not accuse Sinner of intentional doping, but argued that athletes remain responsible for the actions of their support personnel. WADA emphasised that, under Articles 2.1 and 2.2 TADP, an ADRV is established independently of the athlete’s state of mind. Rather than contest the case before the Court of Arbitration for Sport, the parties opted for a negotiated settlement. Invoking Article 10.8.2 of the World Anti Doping Code, they entered into a Case Resolution Agreement. Under its terms, Sinner accepted a backdated three month ban running from 9 February to 4 May. As a result, he served the sanction without missing any Grand Slam events.
While Sinner’s case involved a topical spray, Iga Świątek faced a similar ordeal with a contaminated supplement, highlighting the risks of unintentional doping violations.
Iga Świątek
How did the case against Świątek begin?
In the early hours of 12 August 2024, Świątek submitted an out-of-competition urine sample ahead of the Cincinnati Open. At the time, Świątek was dealing with jet lag and, as she later disclosed, had taken two to three melatonin tablets during the night to help regulate her sleep cycle. In Poland, melatonin is available for purchase over the counter. Her urine sample was divided into A and B samples and sent to a WADA-accredited laboratory in Montreal for analysis. The A sample tested positive for trimetazidine (TMZ), a prohibited substance.
What is trimetazidine and why is it banned?
Trimetazidine (TMZ) is a metabolic modulator prescribed for treating heart-related conditions such as angina. It enhances blood flow to the heart and stabilises blood pressure fluctuations. Since 2014, TMZ has been banned by WADA, and is listed under S4.4 of their Prohibited List as a ‘hormone and metabolic modulator’, due it its potential to improve cardiac efficiency and endurance, offering a possible performance advantage in elite sport. Świątek, who did not possess a TUE at the time of testing, was therefore in breach of these regulations.
Provisional suspension and B-sample confirmation
On 12 September 2024, exactly one month after the sample was collected, the ITIA provisionally suspended Świątek from competing. She was issued with a pre-charge notice for an ADRV, citing Articles 2.1 and 2.2 of the TADP. On 14 September, Świątek requested analysis of her B sample, which confirmed the presence of TMZ at a concentration of 50pg/ML. On 22 September, within the ten-day appeal window provided by the TADP, Świątek formally contested the suspension. Under Article 14.4.1 of the TADP, this appeal paused the public disclosure of the case, as the ITIA is required to maintain confidentiality until a provisional suspension is imposed or accepted, a formal charge is publicly disclosed or a tribunal rules on the alleged ADRV.
In an effort to determine the source of the substance, Świątek and her support team submitted all supplements she had consumed prior to 12 August for laboratory testing, including the melatonin tablets she had used to manage jet lag. These were analysed at facilities in Paris and Strasbourg. Testing revealed that a Polish-manufactured supplement, LEK AM Melatonina, was the likely source of contamination. Further laboratory analysis confirmed that the product contained trace levels of TMZ.
The ITIA subsequently commissioned additional analysis at the Sports Medicine Research and Testing Laboratory (SMRTL) in Salt Lake City. Świątek’s team provided both the opened container used on 12 August and an unopened container from the same batch. Both containers had matching batch numbers and intact tamper-evident seals. On 4 October 2024, SMRTL confirmed the presence of trimetazidine in both containers. These findings were independently verified by a scientific expert from another WADA-accredited laboratory. The ITIA accepted that the contamination likely occurred during the manufacturing process. The company that produced the LEK AM Melatonina also manufactures TMZ-based medication at the same facility, making cross contamination a credible explanation.
Tribunal ruling and reinstatement
The ITIA ultimately accepted Świątek’s explanation that the melatonin she had taken was contaminated with trimetazidine and concluded that the violation was unintentional. Her conduct was assessed at the lowest end of the spectrum under the category of ‘No Significant Fault or Negligence’, which under the TADP, applies where a player’s fault or negligence, when considered in the totality of the circumstances and in light of the criteria for No Fault or Negligence, is deemed not significant in relation to the ADRV. In its ruling, the ITIA acknowledged that although melatonin is a regulated medication in Poland, that classification does not override the athlete’s responsibility under the strict liability standard applied in all doping cases. Świątek’s case was also bolstered by scientific evidence. Hair sample analysis showed no trace of TMZ, and doping controls conducted around the time of the positive test returned negative results. Together, these findings supported the conclusion that the exposure was a one-time event caused by product contamination.
On 4 October 2024, the independent tribunal chair lifted Świątek’s provisional suspension under Article 7.12.3.1 (iii) of the TADP, which permits reinstatement in cases involving product contamination. She was formally cleared to return to competition from 4 December 2024, after serving a one-month ineligibility period, including three weeks of provisional suspension. WADA confirmed that it would not appeal the tribunal’s decision. In a public statement, the agency described Świątek’s explanation as plausible and supported by the scientific evidence. ITIA Chief Executive Karen Moorhouse also addressed the outcome, calling it an exceptional case of product contamination. She expressed confidence in the investigative and scientific processes that led to Świątek’s exoneration.
The swift resolutions of Świątek and Sinner’s cases, though supported by scientific evidence, sparked widespread debate from players questioning the sport’s anti-doping consistency.
Scrutiny and Uneven Standards: Reactions to the Bans
Although Iga Świątek received a one-month suspension, her provisional ban meant she served only one additional week following the official ruling. Jannik Sinner was handed a three-month suspension, significantly shorter than the twelve to twenty-four month sanction originally sought by WADA. Despite relatively short bans and swift resolutions, the cases drew sharp criticism from within the tennis community. Twenty-four-time Grand Slam champion Novak Djokovic commented, “It’s not a good image for our sport. A majority of players feel there is favouritism,” adding, “it appears you can almost affect the outcome if you are a top player, if you have access to the top lawyers.” Nick Kyrgios called the situation a “horrible look” for tennis, while British doubles player Tara Moore, who served a 19-month ban linked to contaminated meat, questioned whether she would have received fairer treatment if she were a Grand Slam champion. These criticisms underscore a broader concern: does tennis’s anti-doping system treat all players equally, or do high-profile stars benefit from greater resources?
Beyond the Ban: What’s at Stake
The cases of Iga Świątek and Jannik Sinner raise questions that go beyond the technicalities of contamination or the duration of their suspensions. At their core, they have forced tennis to confront a more fundamental concern: how can the sport credibly uphold the principle of fairness when its disciplinary procedures appear to favour the well-connected? Anti-doping frameworks are built to hold athletes accountable regardless of intent, but when enforcement appears inconsistent and favours those with greater status or resources, it undermines the credibility of the entire system. The Professional Tennis Players Association’s recently introduced Athlete and Counsel Equity Programme aims to address this by providing all players, regardless of rank, with access to legal and scientific resources, levelling the field in doping disputes. These cases are not mere anomalies to be dismissed and forgotten. As tennis grapples with these high-profile cases, the sport must ask itself: can it rebuild its trust in its anti-doping system or will perceptions of favouritism continue to cast a shadow over its biggest stars?