Chelsea winger Mykhailo Mudryk says he is in "complete shock" after testing positive for a banned substance, as confirmed by the club on Tuesday.

The Football Association (FA) notified Chelsea following an "adverse finding in a routine urine test" provided by the Ukrainian international.

Mudryk has denied any wrongdoing, insisting he has never knowingly used any prohibited substances.

“This has come as a complete shock as I have never knowingly used any banned substances or broken any rules," Mudryk wrote on Instagram.

"I 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.”

Under FA guidelines, players can face provisional suspension following a positive drug test, although the FA has not confirmed whether Mudryk, 23, is suspended or when the test occurred.

FIFA regulations allow bans of up to four years if a player is found to have intentionally taken a banned substance.

Mudryk, who signed for Chelsea from Shakhtar Donetsk in January 2023 for a deal worth up to £89 million, last played for the Blues on 28 November.

He has missed Chelsea’s last five matches, with head coach Enzo Maresca attributing his absence to illness.

With 10 goals in 73 appearances for Chelsea, Mudryk's case remains under investigation, while the Professional Footballers' Association (PFA) is expected to reach out to provide support during this period.