He's going to be a fucking brilliant midfielder in a 4-3-3, which is the system we play and will continue to play. 4-2-3-1 is for football manager and FIFA.
A midfield three of thiago and fabinho plus one other is fine, wins most games. Problem is if they miss games then you need to be able to trust the guys who come in, and clearly we don't. Milner at this stage shouldn't start a big game