Erling Haaland was asked for his autograph by assistant referee Octavian Sovre after Borussia Dortmund’s 2-1 defeat to Manchester City on Tuesday night.
The Dortmund striker, who set up Marco Reus’ away goal before Phil Foden’s last-gasp winner for City, was filmed signing the linesman’s flag in the tunnel after the game.
Describing the incident on BT Sport, former Premier League stars Owen Hargreaves and Joleon Lescott slammed the official’s behaviour.
Former Manchester United midfielder Hargreaves said: “They had a difficult first-half and they got a lot of things wrong in that first-half.
“You can be a fan, but you can’t do that in front of the other players, it just doesn’t look right.”
Lescott added: “There’s never a right time for that, it just doesn’t bode well for the officials. It’s a childish thing to see.”
Haaland, 20, is one of world football’s biggest stars and no player has been written about more over the past few weeks.
The Norway sensation has been linked with most of Europe’s top clubs ahead of a potential transfer this summer.
City are one of those clubs – and while Haaland could not add to his incredible Champions League record at the Etihad, he was involved in the Dortmund goal.
Kevin De Bruyne opened the scoring for City, before some questionable officiating led to Jude Bellingham having a goal disallowed for Dortmund.
The visitors eventually got their away goal in the 84th minute when Haaland played a delightful first-time ball to Reus, who converted past Ederson, but Foden restored City’s lead before the full-time whistle.