Manchester United Message Board
Taking out all players 30 and over the basis of future squad looks like this:
Goalkeepers; de Gea, Lindegaard
Defenders: Smalling, Jones, Evans, Fabio, Rafael
Midfield: Fletcher, Anderson, Cleverley, Young, Nani, Valencia, Morrison, Pogba
Strikers: Rooney, Hernandez, Macheda, Welbeck
Obviously there need to be additions, especially in defence, but some of those might come from the youth team such as Thorpe, McGinty, Tunnicliffe, Cole, Cofie and Keane
A very promising bunch of players there. A little early to include a few of them in the first lists you've made as appose to listing them with the other youth players you mention at the end though.
Good luck to all the young players that are yet to make their debuts.