Some very interesting comments.
I'll add a few of my own.
When we talk about youth development there are three basic factors you have to manage...if you make an assumption that the player is already technically capable.
1. Emotional capability (managing pressure, dealing with senior feedback, motivation, confidence, self-regulation)
2. Physical capability (obvious stuff like pace, stamina, strength on/off ball)
3. Intellectual capability (responding to tactics...inc opponents, decision making, speed of thought and application etc)
Doing all of these things at U/18 and reserve level is one thing...doing it at senior level is another. Doing it CONSISTENTLY as senior level is even harder for most. It takes time.
Some players need these tested. So let's include him in the squad to develop some of the above points but he's not ready to play just yet. For others, lets give him 20 mins, half a game or a full game and see how he goes. He may get multiple chances over a period of time (Chong is a good example)...but he isn't quite ready.
Other players make the jump really quickly (like Rashford) and it's a bit of a surprise. At least to supporters. But the coaching staff usually have a good idea as they see him in training and that's why he is suddenly included in the squad.
You can only integrate players properly when the above three things are all aligned. At the moment, maybe the coaching staff (for many different reasons like COVID, chasing the league, injuries etc) don't feel that any of the current crop of juniors are ready. So they are doing things slowly with the likes of Tuanzebe, Williams and even Greenwood. In addition others are out on loan because they need the experience and the pressure is too high at United. You only have to look at the dickheads on Twitter and on here to see how some youngsters get absolute shocking comments. So let's send Mengi, Garner et al out on loans.
Then there are other players who are under contract but sent out on loan because they won't make it...but the club is creating space for others like Shoretire to come through.
In addition, most young players lost half a season in 2020 and aren't getting that much game time this season. That will put them back.
In fact, this is actually a really good indicator of youth development. Whilst the ideal is to get a youth player into the first team every season, it doesn't work that way. There aren't enough spaces for one....they have to better than the current incumbent for two...and they have to be ready.
I would have loved to see Mengi get a chance at Luton. But maybe the club already knew what was needed in terms of his development and playing in a first team game wasn't part of that plan. Maybe Bailly needed game time next to Maguire as Solskjaer was trying to see what his best central pairing would be. Who knows.
I would like to have seen Shoretire get 10 mins at Real Sociedad over Mata. Maybe Solskjaer thought that was a step too far given his development to date. Who knows.
Finally, I would argue that Solskjaer has 'integrated' a number of players into the first team in Greenwood, McTominay, Tuanzebe, Williams and Henderson all in different ways. Some are doing better than others. But to say he isn't integrating youth just isn't true in my mind.
I'm hoping that in the next couple of seasons Elanga, Mejbri, Shoretire and one or two others get a chance. But to make that happen, Elanga has to better than Rashford...Mejbri/Shoretire have to be better than Fernandes and Pogba...they need time to do that. In training, with cameo appearances and out on loan.
Our history shows being patient and trusting the coaches works out in 99% of cases. There aren't many players to come through our system...not be 'integrated' properly and then perform brilliantly somewhere else. Five players max in 50 years in my opinion.
Let's leave it to the coaches, watch the youngsters grow, enjoy it when they get a chance and cross our fingers that we've found another gem!
I swear the Caf is obsessed with height. I think he's taller than Diallo by a fraction but both haven't finished growing yet.