Ruben Amorim has claimed that his squad is missing 'crazy guys' who step up in difficult situations.
The Portuguese boss, who has been afforded a huge amount of time to turn a dire situation at Old Trafford around by United chiefs, has come under increasing pressure this season.
After spending almost £250million in the summer, his side are already out of the Carabao Cup and languishing in 14th place in the Premier League having lost three of their opening six fixtures.
While Amorim's job is not thought to be immediately under threat, if results don't improve soon that's likely to change. United face Sunderland at Old Trafford on Sunday in what seems a crucial fixture in terms of the manager's future.
And speaking to TNT Sports ahead of the clash, the 40-year-old former Sporting Lisbon boss outlined exactly what he feels his squad his missing.
'We have a lot of players that were here for many years and we are struggling so that is always in your mind,' Amorim told Owen Hargreaves.
Man United boss Ruben Amorim has claimed his struggling squad needs more 'crazy guys'
The Red Devils slumped to a disappointing 3-1 loss at Brentford on the weekend
'It's not just the leaders, we need leaders, but sometimes what I'm thinking is we miss some crazy guys, you know?'
He added: 'The guys. I think (Matheus) Cunha is a little bit like that. He's a guy that is a good guy but who doesn't care who you are. He can play wherever and he will go with the ball.
'This kind of feeling, we need that. Harry Maguire was captain and played for the national team, but you can feel sometimes that when things are going wrong we go down. No matter if it's Bruno (Fernandes) or Harry and that is in the past, we need to live in the future.
'Sometimes you look at the pitch when something is going really wrong and you see Bryan with a different light, because he came from a different environment. Then you look at Cunha and you feel that sometimes he is frustrated but you can feel the frustration is something like - give me the ball - so we miss that.
'We need to forget the past, we need sometimes that crazy guy. The world can be on fire, but I don't care. Sometimes it's not just the leaders. It's the maverick guys.'
Cunha and Mbeumo joined the Red Devils on the back of two stellar seasons at Wolves and Brentford respectively for a combined fee of around £150m.
While they're yet to set the world alight at United, both stars have shown glimpses of their talent and have certainly boosted a front-line which struggled so badly last season.
Mbeumo, who has two goals to his name in the red of United thus far, admitted the entire team 'need to do better' in an interview this week.
Amorim singled out new recruit Matheus Cunha as an example of a 'crazy guy'
He also pinpointed Bryan Mbeumo as a star who doesn't fold under pressure
United host Sunderland at Old Trafford on Saturday in what seems a must-win game for Amorim
'Obviously disappointed with the result (against Brentford),' he told Sky Sports, 'when you play in a club this big, everyone needs to know what to do. As a team, we need to do better.
'The only thing we want to be focused on is ourselves, we just try to listen to what's going on inside.
'It's not that hard (to block the noise from outside the club out), the main thing we see is on social media, so it's just not going on there much, and you just have to stay focused on your own things.'
United's fixture against Sunderland, who travel to Old Trafford off the back of an impressive win at Nottingham Forest, kicks off at 3pm on Saturday.