Alejandro Garnacho snapped at YouTuber Planet Faz after he tried to give the Manchester United star advice outside Old Trafford ahead of his side's victory over PAOK in the Europa League.
The Argentinian has had a mixed campaign so far, with six goals and four assists in all competitions but just one return in his last six league matches.
His form has summed up a United side that has slumped into 13th place and sacked Erik ten Hag as manager last week after club bosses ran out of patience with the disastrous start.
Interim boss Ruud van Nistelrooy has steadied the ship somewhat and led the Red Devils to their first Europa League victory of the season with a 2-0 win over Greek side PAOK on Thursday night.
Ahead of the match, Garnacho was accosted by Planet Faz as he was signing autographs and the social media figure embarked on a remarkable pep talk, featuring three pieces of advice.
He said: 'Garnacho, you got to pass better today yeah, please. Pass better today, score a goal, and work on your first touch as well, yeah?'
After the winger finishes meeting the other fans, he turns to Planet Faz, who is filming the encounter, and issues a brutal response.
'Why are you not playing man?' he asks, before striding away.
The YouTuber seems to chuckle to himself before saying: 'He did not like that, eh?'
Planet Faz boasts 26,000 subscribers on his YouTube channel and has posted more than 750 videos to his channel, mostly about Man United.
In his channel description, he says: 'Welcome to Planet Faz! I'm Faz, a match-going football fanatic! I go to every single Manchester United game! Men, Women and Youth games in Old Trafford! I try to attend games in the youth football facilities too!
'On this channel, you'll find exclusive matchday squad clips, clips from the BEST SEATS in the stadium (I SIT [sic] BEHIND TEN HAG) & regular live streams relating to football and other sports! Occasionally some vlogs and other content too!'
After a slew of criticism for his treatment of Garnacho on social media on Thursday night, Planet Faz took to X to defend his actions.
'Wanting a player to get better and telling them that, as you have high expectations for them, is now considered rude,' he said 'You're all hypocrites. End of.'
Garnacho endured another difficult night in a United shirt, finding himself in a number of good positions but continuing to struggle with his end product, and was hooked for Marcus Rashford on 65 minutes.
In the end, it was the man on the other flank, Amad Diallo, who was the difference between the two sides as his second-half brace edged the home side to a long-awaited European victory.
Ruben Amorim will join United as the club's new boss this month having made the switch from Sporting Lisbon and Garnacho will be hoping to cement his place in the side under the Portuguese manager.
