Shakhtar Donetsk's Croatian midfielder Darijo Srna suspended his career on Friday after his Ukrainian club announced he had failed an out-of-competition drugs test.

"Shakhtar Donetsk is aware that an out-of-competition test on Darijo Srna was positive on March 22, 2017," said Shakhtar in a statement.

"The player is not banned from the sport. However, after consulting the club, Darijo Srna has taken the decision to no longer play until the case is resolved and so that he can concentrate on his defence.

"The club respects Darijo's decision and is convinced that he will restore his reputation."