Some much more likely options from the championship
Kiernan Dewsbury Hall (Hull) 21
Elijah Adebayo (Luton) 24
Max Bird (Derby) 21
Jason Knight (Derby) 21
Joe Worrall (Forest) 25
Tyrese Campbell (Stoke) 22
John Swift (Reading) 26
Naby Sarr (Huddersfield 28
Sorba Thomas (Huddersfield) 22
Now none of them are under 20 so they might not be for you. But these have been the best players in the league this season...barring the obvious Mitrovic, Diaz, Johnson, Garner etc etc.
Worrall would be ideal for us i'd say, only problem we have i(similar to Johnson) is Forest are likely to be playing in the Prem next season (they can even go up automatically as Bournemouth are flagging and they play each other).
All these would be automatically ready to step into the first team squad as even the younger of this selection have played around 100 first team games