Sheffield United's Oli McBurnie has been reminded of his responsibilities by the Football Association after appearing to make an obscene gesture while watching Swansea City.
The 23-year-old striker, who joined United for a record £20m in August, is a Swansea fan and was in the crowd for their derby at Cardiff City on Sunday.
McBurnie had Sunday off after scoring in the 1-0 win over West Ham on Friday.
Sheffield United are not commenting on the incident.
The Scotland international, who has scored four goals for the Blades since his summer move from Swansea, was also pictured watching his former team at QPR earlier in the season.
Former Manchester United and England defender Gary Neville said - before the FA's notice was issued - that any action against the player would be "a disgrace".
Neville said on social media: "This lad has done the most normal thing I've seen from a footballer for a long time. He goes to support his team and is pictured, filmed and ends up with this."
Former Swansea forward Lee Trundle added: "Exactly mate, people moan that players are too far detached from the fans then when one has a day out as a fan they do this."
In November, McBurnie pleaded not guilty to a drink-driving charge at Leeds Magistrates' Court. He is due to go on trial on 16 March.