Garnacho was involved in a brief altercation with a supporter before United's 2-0 victory over PAOK in the Europa League last week, with the fan telling the Argentina international winger that he should 'pass better' and 'work on his first touch'.

The Red Devils star did carry on signing autographs for other fans before he glanced back in the supporter's direction and said: "Why are you not playing, man?"

Garnacho responded to the criticism in stunning fashion when he scored United's third goal in the win over the Foxes but opted for a muted celebration in front of the Old Trafford supporters.

But Keane insists Garnacho should have put the incident with the supporter aside and feels the 20-year-old should get a job somewhere else' if he feels he cannot celebrate with the fans.

"Can I tell you something, whatever about this game and we know these younger players suffered but if you can't celebrate a goal there's something drastically wrong with this game," Keane said on The Overlap's 'Stick to Football'.

"Whatever is going on off the pitch for any player, it could be family stuff, when you score a goal, you work all week, you're playing the game to score a goal. But no criticism should ever affect you celebrating a goal.

"Famous last words, 'I'm different'. When you score a goal there should be nothing else on your mind. They're playing a game to score goals, they've got fans who have travelled and paid fortunes to get there, and he's on about, 'someone's had a go at me'. People have travelled, you've scored a brilliant goal and enjoy it, get upset with people, and he can make his point on social media.

"Celebrate a goal, that's what fans travel for. People make sacrifices to travel to watch Man United, he scores a brilliant goal, United are having a tough time and if a young player can't enjoy scoring a goal for Man United do you know what he should do? Get a job somewhere else. If he's working in a factory somebody would be giving him stick in the factory."

Speaking about Garnacho's refusal to celebrate, United captain Bruno Fernandes said after the game: "Garnacho scored a banger but didn't celebrate like he should because he thinks he has lost faith from some fans.

"I told him people will always moan but lots of people like you and enjoy what you do.

"I told him to celebrate, it was something special. He is a special player, we have difference makers.

"They are the ones who win us games. We want them to score every game but that isn't going to happen."

Keane, meanwhile, believes current players are too concerned with things said about them, especially with social media so prevalent.

He added: "There are idiots everywhere but my point is, when you score a goal, that's gone. If he's going to be upset with that, get a different job.

"Why do they get worried about a guy on social media? What happens, they have a go at a player with their phones ready so you have a go back. Idiots, honestly."

New Manchester United manager Ruben Amorim is reported to have identified Flamengo's teenage star Lorran as his first signing at the club with Antony used in a swap deal and with the Brazil international coming to a big realisation over his Old Trafford future.

Meanwhile, United and Arsenal are reportedly ready to head-to-head in the transfer market to sign the most valuable free agent in the game next summer.

Bayern Munich winger Leroy Sane has emerged as a top target for both Premier League clubs, who will be looking to bolster their forward options ahead of next season – particularly in the wide areas.

Landing a player of Sane's quality on a free transfer is a no-brainer, even if it means Man Utd or Arsenal will ultimately be saddled with a large salary as a result.

And German publication Bild reports that United and Arsenal are ready to go toe-to-toe in the battle to sign the Germany international.

Man Utd legend Roy Keane slams Alejandro Garnacho's muted celebration