He's quite clearly going to be a centre mid though rather than an attacking mid, and I'm sure Martinez has said he sees him in a deeper role long term so he's gonna have to put him there at some point.
I disagree. I've seen nothing from him to suggest he can do any defending at all. For a big lad, he seems to never ever get his head on the ball. He's an attacking midfielder, his best tribute is running at a defence with real strength and power.