Chelsea announced on Tuesday that had been notified from the Football Association regarding an irregular finding in Mykhailo Mudryk's urine sample.
The London-based club confirmed that the 23-year-old Ukrainian forward had never intentionally consumed prohibited substances, whilst Mudryk expressed his astonishment at the findings.
"Chelsea Football Club can confirm that the Football Association recently contacted our player, Mykhailo Mudryk, concerning an adverse finding in a routine urine test," the club's official statement read.
"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."
The Ukrainian international addressed the situation through his Instagram platform.
"I can confirm that I have been notified that a sample I provided to the FA contained a banned substance," he stated.
"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."
