Chelsea head coach Enzo Maresca said he believes Mykhailo Mudryk did not knowingly take a banned supplement.

The 23-year-old has missed the last five matches having returned a positive drugs test with the club confirming on Tuesday the reason for his absence, having previously claimed that he had been missing through illness.

Mudryk said in an Instagram post that the results of his ‘A’ sample had come as a “complete shock” and insisted that he not intentionally taken a banned substance, reported in Ukrainian media to be meldonium.

“We trust Misha,” said Maresca. “When this kind of thing happens you need to support your player in all aspects.

“Misha is a Chelsea player, it’s my duty to be in contact with him. Me, the club, his team-mates, we are all there. Trust means we believe Misha.”

The PA news agency understands Mudryk has been provisionally suspended as a result of the failed test.

It is understood that a result is yet to be returned on a second ‘B’ sample used to confirm the veracity of the test on the original sample.

In a statement issued on Tuesday, the club said: “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 Ukraine international has struggled for consistency since joining from Shakhtar Donetsk in January 2023 for £88million, making 53 Premier League appearances but scoring only five goals.

This season he has mainly played in the Carabao Cup and in the Conference League with Maresca using him only sparingly as a substitute in the league.

The head coach said he expects Mudryk to still have a future at Stamford Bridge following any long-term suspension that may be handed down.

“I think he’s going to come back, the only thing is we don’t know when,” said Maresca. “The only doubt we have in this moment but for sure he’s going to come back.

“Any player in the world when this happens, they need support. No matter if he’s 20 or 30, no matter if he’s English or Italian or Ukrainian. When this kind of thing happens, we all need support. It’s not about his age or his country.

“It is my duty since we started. I try to have a quite close relation with the players, because I like it that way.

“With Misha it is exactly the same. I’m there to try to help him in anything he needs because in this moment it’s normal that he’s going to need help from the club, from me, from his team-mates, and we are all there to try to support.”

Defender Josh Acheampong has signed a new contract until 2029, bringing to an end a stand-off with Chelsea over his future.

The 18-year-old had been told he would not play for the club again until he agreed to a new deal having  previously pulled out of a verbal agreement.

“Finally the club has found an agreement and we are all happy,” said Maresca, who indicated he would not be sent on loan.

“He can be a great player for this club. My personal opinion is that he has to stay close to us. If we can keep him here it’s much better.”