The appeal to the Switzerland-based Court of Arbitration for Sport (CAS) means that the case might not be resolved before Jannik Sinner begins defense of his Australian Open title in January.

The Italian champion is almost certain to end the year as world number 1, but his main goals before the end of the season are the Nitto ATP Finals in Turin and the Davis Cup Finals in Malaga. Last year, Jannik had dragged Italy to a historic Davis Cup triumph after losing the ATP Finals final to Novak Djokovic.

World Anti-Doping Agency is appealing the "no fault or negligence" finding in Jannik Sinner's anti-doping investigation for clostebol.