The incident occurred after the first leg, played at Celtic Park in Glasgow on February 15, of the recent UEFA Europa League tie between Zenit and Scottish champions Celtic.

UEFA had chosen Poloz for a random drugs test, meaning the Russian international had to go directly to the doping control room for a test before joining his teammates in the dressing room.

The 26-year-old striker, however, who did not play in the match, instead, headed straight to the dressing room.

This led to UEFA, European football’s governing body, issuing a warning to the club.

As reported by the Scottish Sun, Zenit issued a statement in response which read: "UEFA did issue a warning to the club – that is standard procedure when the doping officer includes it in his report.

"In this case our player, Dmitry Poloz did not have time to stop and he went to the dressing room through habit."

The Zenit statement continued: "Our medical staff immediately informed him he had to go to the doping room.

"He did not spend any time in the dressing room.

"We would also point out at Celtic Park, the dressing rooms are very close to the tunnel too.

"Therefore, the UEFA warning is only of a preventative nature."

After losing the first leg 1-0 at Celtic Park, Zenit won the second leg 3-0 at the Krestovsky Stadium - a match in which Poloz again remained on the bench - to qualify for the next round of the tournament.

The former Russian champions, however, were eventually knocked out of the competition by German club RB Leipzig by a 3-2 scoreline over two legs.