This youngster show great promise and very strong athletic management. Now here's where the fun part starts - let him play as much baseball as he can reasonably handle... just for the fun of it. He'll come along nicely because he's having a good time. His natural athletic ability coupled with his form as I see it now will slowly develop into a solid player at this position.
I hesitate tp suggest.. do this... do that, because at nine(9) years old, he's going to develop, mature, grow and progress at different rates as he gets older. So, what works now will change as he gest older, puberty sets in, and his hormones kick in.
I'm sure you're going to enjoy his progress. He has all the makings of going a long way in this game.