Normally, I'd say that you should only train 1v1 during two game weeks for at least this season,and possibly next season, too.
I see that you don't seem to have any other trainees. I recommend picking up one or two other guys to train along with him. It will help your team, even if you don't keep them. If you stick with just the one guy (or even if you pick up one more), I see no reason to train anything other than OD, PA and JR this season. Pick up a couple more guys and work in some 1v1next season while still focusing on OD. PA and JR. Then see how he's shaping up and decide if you need to adjust.
Leave 1v1 training alone this season.
Did I mention that you should stick with OD, PA and JR?
Good.
OD, PA, and JR!