Maria Sharapova will face a hearing for testing positive for meldonium, despite the World Anti-Doping Agency issuing fresh guidance on the banned substance.
Wada said on Tuesday athletes who tested positive for meldonium before 1 March could avoid bans.
But the International Tennis Federation said Sharapova's case will proceed.
The Russian tested positive for the drug at this year's Australian Open, after it was added to Wada's banned substances list from 1 January.
Wada's change in stance is due to a "lack of clear scientific information on excretion times", meaning the agency has so far been unable to establish how long it takes for the drug to clear the human body.