I've had two perennial allstars make U-21.. With skills not too far off of this guy. The only problem is his height could be better, other than that he is a good trainee. But, I'm not the person to ask about if your guy will make U-21 or not.
It's your personal preference. If you're working with some big men right now, then don't. But, this guy is a good trainee, no doubt.