I would treat "him" as I treat all my players except GoalKeepers :
Use "him" and train "him" up with my team and then sell "him" before he becomes expensive.
If "he" is not sold, no mourning and good luck for any other TeamLeader signing "him".
Hihi, not a professional Strategy I guess, but ... . . ..
I like the way you would treat "him" throughout the career lifecycle :-) - you are in the draw.