The World Anti-Doping Agency (WADA) has appealed to the Court of Arbitration for Sport (CAS) against the decision to clear world number one tennis player Jannik Sinner of wrongdoing after he twice tested positive for the banned steroid clostebol. Despite Sinner’s explanation that the substance entered his system through a massage from his physiotherapist, WADA argues that the finding of 'no fault or negligence' was incorrect. WADA is seeking a suspension of one to two years for Sinner but is not asking for the disqualification of his past results beyond what has already been imposed. Sinner, who won both the Australian Open and the U.S. Open this year, was previously stripped of ranking points and prize money from the Indian Wells tournament where the first positive test occurred.