Tennis player Jannik Sinner schedules appeal hearing at sports tribunal for doping allegations in April.

LAUSANNE, Switzerland — Jannik Sinner, the top-ranked tennis player, is set to appear before sports’ highest judicial body in April amid an appeal from the World Anti-Doping Agency (WADA) that aims to impose a ban of at least one year on him.

The Court of Arbitration for Sport (CAS) announced on Friday that a private hearing is scheduled for April 16-17 at its headquarters in Lausanne, Switzerland. While the CAS did not provide a specific timeline for delivering its decision, the involved parties might request an expedited ruling prior to the French Open, which begins on May 25.

WADA is contesting a decision made last year by the International Tennis Integrity Agency (ITIA), which opted against suspending Sinner, ruling that the presence of a banned anabolic steroid in his system was due to accidental contamination. Sinner argued that trace amounts of Clostebol found in his doping sample were a result of a massage from a trainer who had used the substance after an injury. This explanation was accepted by the governing body.

In September, Sinner triumphed at the U.S. Open, even as details of his situation came to light. The case had been shrouded in confidentiality since April when he successfully appealed against a provisional ban that had prevented him from competing.

The 23-year-old from Italy has encountered skepticism from peers, including renowned player Novak Djokovic, who have alleged that he received undue leniency from tennis officials. The ongoing inquiries related to this issue have followed Sinner as he prepares to defend his title at the Australian Open this week.

WADA is pushing for a suspension of Sinner that could range from one to two years.