The World Anti-Doping Agency has appealed against the decision to clear world number one Jannik Sinner of blame after he twice tested positive for a banned substance.
Wada said last month's ruling by an independent tribunal to find the Italian had no fault or negligence was "not correct under the applicable rules".
It has appealed to the Court of Arbitration for Sport (Cas) and says Sinner should be banned for "between one and two years".
Sinner, 23, was on court against Roman Safiullin in the last 16 of the China Open in Beijing when Wada's appeal was announced.