If they got much potential with good training schedules they just should raise attributes faster than others.
In my games I haven't noticed that my youngsters develop much better while on loan they just get some match practice, but here I might be wrong.
And when they're ready to play in first team just let them play and wait. And whem you see that one of profilic players is much better in psychical than technical attributes you can set him some individual schedule with more emphasis on techinque. | 
