CROATIAN defender Domagoj Vida was booed every time he touched the ball in the World Cup semi-final against England after shouting "glory to Ukraine" in the aftermath of his side's victory against the host nation Russia in the quarter-finals.
Domagoj Vida claimed he was not trying to bring politics into football with his comments.
But under FIFA rules, players are banned from making political statements or gestures.
Domagoj Vida was issued a formal warning by the governing body, which is looking into new footage that has emerged of the incident.
Vida used to play football in Ukraine for Dynamo Kiev, a team in the country’s capital.
The defender made the comments in a video alongside Croatian coach Ognjen Vuckojevic after the Russia game on Saturday.
However, the coach was sent home and will play no further part on the Croatian coaching staff at this tournament.