I think a whole can of food might be a little much..
If you're free feeding and he's eating well, then I wouldnt both with the canned unless you can to do it every once in a while for variety or as a treat. I would probably do 1-1.5 tsp max, though.
If you want to feed on a schedule, I would put a little of the canned on top of the dry and feed that 2-3x a day depending on his age and weight
I hope that made sense!