Veteran right-back Darijo Srna will play no part in Shakhtar Donetsk's trip to the Etihad Stadium on Tuesday after the Croatian tested positive for a banned substance, according to The Sun.
Srna has won nine Ukranian Premier League titles during his 14-year spell in Donetsk, moving to the Donbass Arena in 2003 from HNK Hajduk Split for just €1.2m.
The 35-year-old has taken a self-imposed break from football in an attempt to clear his name of any wrongdoing and will not travel with the rest of the Shakhtar Donetsk squad to Manchester on matchday two in the Champions League group stage.
"First and most important, I would like to make it clear that I have never knowingly or intentionally taken any prohibited substance, nor unfairly intended to gain a competitive advantage," Srna said. "I am investigating the possible source of the substance and am co-operating fully with NADCU in this respect.
"In order to focus on my defence and avoid any undue distractions for the team, I have made the decision to refrain from playing until the on-going legal proceedings have been resolved.
"I will now be focused entirely on clearing my name and reputation," he added. "Over the course of my entire career I was always under the impression that I had to persistently prove myself over and over again.
"This is not the end of my career, I can promise you that."