Difference in physical prowess. I'd imagine he was more of a standout as a youth teamer. Not the same in men's football, still big, not so quick.
I agree with what you're saying about physicality, I just meant if he was a winger as a youth player you'd see the natural instinct for him to attack a full back coming back to the fore. As it stands that instinct doesn't seem to be there at all to me.