He can play CB in an emergency, if you asked him to come to City and be a CB he'd hang up the phone.
For all his faults, Koeman showed De Jong's an 8, and the closer to goal the better. Playing that role last season he was arguably Barcelona's best player (which meant something when Messi was still there). He has a lot of similarities with Gundo last season, but I don't see how it ever fits.
Even if Gundo and Bernardo goes, Foden and Grealish are destined for the centre sooner or later, the club rate McAtee, there's no room for a 26 year old on €400k/week.