If he were starting a bit further forward his burst would be more deadly in terms of getting to the byline. Not sure he has the rest of the attribute in him, though. Not a great crosser, doesn't go on mazy dribbles, inconsistent touch, and not a finisher.
Can't help but think he's an absolute liability at fullback, and that wingbacks are for the birds. Does alright in a pinch, and never thought he was as good on the right as he is from the left. Having his strong foot on the outside kills the rest of his midfielder-y game.
I'm less concerned with the "switching off" accusation, more concerned that he might just not have another level. That is, if he is gonna start for us longterm. I just don't see it.
EDIT: He is still very young, and I hope he really explodes into life next season, for the record. I think Emery needs to tell him where he's going to play (or what role, predominantly), and that will help tremendously.