#1 Andreas Pereira
Andreas Pereira is the most experienced of the lot after good loan moves to Granada and other championship clubs and he is currently now at Valencia playing in the first team week in and week out and has played against the likes of Messi and Ronaldo. Jose Mourinho even wanted him to stay, but the Brazilian wanted to play regularly and opted to move to Spain on loan and is currently very successful.
Among the entire crop of youngsters in this list, Andreas Perreira has a very good chance of featuring in the Manchester United first team regularly. With midfield a huge problem for United, Pereira could seamlessly slot in and play anywhere in midfield. The best part is that he still does not have a preferred position and plays well at anywhere he is asked to play. Mourinho could mould him in any way he wants him to play.