Sharmin,
What do the doctors say about little A's bone strength? Is it normal? If it is, I would let him try it. Even though there is checking, it won't be as hard hitting as what he'll see when he is older, so now may be the time to determine if this is something he can continue to pursue. I think this is something that will be much better learned at this age, rather than waiting for him to grow before he returns to playing, as the contact level will not be nearly as rough as when he is in his mid to late teens.