Chelsea winger Mykhailo Mudryk is appealing to the Court of Arbitration for Sport after he was given a four-year ban by the Football Association for doping.
CAS has confirmed it received his appeal against the FA on February 25. The FA, Chelsea and the player's lawyers have not commented.
Chelsea signed Mudryk for ÂŁ88m from Shakhtar Donetsk in January 2023 and he still has five years left on his contract.
The positive test was for the prohibited substance meldonium but Mudryk believes his sample was contaminated when he was on international duty with Ukraine in October 2024.
Mudryk was provisionally .
In a statement the same month, Mudryk said his failed drug test was "a complete shock" and said he had "not done anything wrong".
Chelsea launched their own investigation shortly after the FA's began, and said the then 23-year-old insisted he "has never knowingly used any banned substances".
The Ukraine international, signed from Shakhtar Donetsk for ÂŁ88.5m in January 2023, last played and scored for Chelsea in a 2-0 win at German side Heidenheim in the Conference League on November 28, 2024.
Now 16 months on from his initial suspension, Mudryk maintains he is innocent. He has been keeping fit by working with his own personal trainers away from Chelsea's Cobham training ground. Chelsea will allow the process to take its full course.
Your Site News chief correspondent Kaveh Solhekol:
"The only reason we know Mudryk has been banned by the Football Association is because it's been confirmed by CAS that he has appealed against it to them.
"The FA themselves have said absolutely nothing, because this is a confidential process. Chelsea have said nothing, and the player's lawyers are saying nothing either.
"Mudryk was a big-money signing for Chelsea. He's not played for them for almost 18 months. He gave a doping sample while he was on international duty with Ukraine, not when he was playing for them.
"That tested positive, and we believe it was for meldonium. He was provisionally suspended by the Football Association in December 2024, and we found out last June he was charged with an anti-doping violation by them.
"Since then, there has been radio silence. We've not known what's been going on - until today.
"If he loses his appeal, as he has been provisionally suspended for nearly 18 months already, you would think he would not be able to play until the end of 2028. That would be a bitter blow for the player, and for Chelsea as well."
