He doesn't have the natural instincts of an attacking full-back. Case in point, at one time down the left, Pogba and Martial, were interchanging, which pulled the right-back in, leaving a wide open space down the side of the 18 yard box to run into. Not noticing this, Martial had to physically point to him to tell him where to run, which Shaw then did but took a heavy touch and got tackled. He does this quite often. He has the defensive instincts, but he's going to need some encouragement and coaching to get him to do things automatically.