FA Youth Cup winner Ben Thornley has warned Hannibal Mejbri about his on-field histronics.
Big things are expected from Mejbri as his reputation grows, particularly after a superb performance earlier this month in the EFL Trophy. Mejbri scored once and also created a goal in the U21 team's victory over local rivals Salford City.
The midfielder is also seeing action in the U23s this season and Thornley, who calls Prem 2 games for MUTV, United's in-house TV channel, admits Mejbri needs to be careful with his on-field body language and how it comes across to teammates.
In his column for Tribalfootball.com, Thornley declared: "Now Mejbri is a very talented player but the other night they didn't give him any time on the ball and they are a big strong, quite physical Leicester side. And he very quickly became frustrated. Sometimes when you see that from the sidelines, when you get foreigners start waving their arms around and showing dissent, that can get to your teammates, you've just got to get on with it.
"Hannibal is only young, but when he is stepping up to play in the U23s on a regular basis, which he will do this season, he has got to realise that he is coming up against bigger, better and stronger players and he needs to learn that he's not always going to be the top dog on the pitch, especially when you've got somebody who won't give you a lot of time and is stronger than you."
A £9.3m signing from AS Monaco last year, Mejbri has been fast-tracked through United's academy system. But Thornley says the 17 year-old needs to recognise he's playing against bigger, stronger players at U23 level and will be frustrated at times in games.
He continued: "He's going to have to learn how to adapt to that and beat it. That's what is going to make him a better player, learning to combat how these players are going to come up against him, especially when they know you are talented.
"But what he can't be doing is showing dissent to his other teammates because that is certainly one way for anyone to start incurring any resentment. He has to be stronger than that mentally. He's a very talented player but he has got it in him to let his teammates down by doing something rash and getting himself sent off because he is frustrated with the treatment he is getting from the opposition."
Thornley, who won the FA Youth Cup in 1992 playing alongside the likes of David Beckham, Gary Neville and Ryan Giggs, says Mejbri's antics could draw resentment from teammates unless he recognises he needs to shut things down immediately.
The former England U21 winger added: "What you don't want, as a local player, is seeing someone who has been brought from overseas to get special treatment from the coaching staff just because they might be a little bit temperamental. That could also start some resentment in the dressing room because players will think 'oh its okay for him to do it but if we did it we'd be in trouble'. Everybody has got to be treated equally."