The London-based club confirms the 23-year-old tests positive for a banned substance.
Chelsea player Mykhailo Mudryk has failed a doping test, the Premier League club says, as reports state the Ukraine international has been provisionally suspended.
The Blues said they were notified by the Football Association (FA) of an “adverse finding” in a urine sample provided by the star winger.
“Chelsea Football Club can confirm that the Football Association recently contacted our player, Mykhailo Mudryk, concerning an adverse finding in a routine urine test,” a club statement said on Tuesday.
“Both the club and Mykhailo fully support the FA’s testing programme and all our players, including Mykhailo, are regularly tested.
“Mykhailo has confirmed categorically that he has never knowingly used any banned substances. Both Mykhailo and the Club will now work with the relevant authorities to establish what has caused the adverse finding.”
Mudryk issued a statement via his Instagram account.
“I can confirm that I have been notified that a sample I provided to the FA contained a banned substance,” it said.
“This has come as a complete shock as I have never knowingly used any banned substances or broken any rules, and am working closely with my team to investigate how this could have happened.
“I know that I have not done anything wrong and remain hopeful that I will be back on the pitch soon. I cannot say any more now due to the confidentiality of the process, but I will as soon as I can.”
Athletes are warned on the United Kingdom Anti-Doping (UKAD) website that they face a ban of four years if they are found to have intentionally taken a banned substance.
If violations involve a specified substance or a contaminated product and athletes can demonstrate they had no significant fault, ineligibility may range from two years to a reprimand, depending on the level of fault.
Mudryk has made 15 appearances for Chelsea this season and last played in a 2-0 win at German side Heidenheim in the Conference League on November 28, in which he scored his third goal of the season.
He joined Chelsea for a reported 88.5 million pounds ($112m) from Ukrainian club Shakhtar Donetsk in January 2023.