go to scouting..
on the filters, select age maximum 20/21, or lesser if you want...
then select certain attributes you are looking for..
for eg, start with finishing at 20, come down to 19-18-17, and look at the players there..
determination would be utmost important..
for CD/DM look for Marking, Tackling, Positioning, Anticipation, Decisions...
for LB/RB look at pace, acceleration, crossing, okayish marking and so on..
for AMC/MC look at passing, flair, decisions, long shots, team work...
anything above 15 on these major attributes, and that should be a proper Regen...
GK: one on ones, reflexes, handling...