Have to disagree with this. After that Everton debacle and also Anderlecht, Mourinho knows better than to put him in a holding mid. He is too slow to intercept and tackle perfectly, and his aerial presence is not much needed when you have the centre backs doing their jobs well. Only reason he is back defending is from set pieces or if we are bombarded. Else he will be a forward pressing player like as can be seen when he played against Chelsea. His main attribute is he provide an outlet for direct balls from De Gea, where he wins more than 50% of the duels and keep the ball well. It is so simple, one punt upfield, chest control, release and you have bypass half the opponent team and you are attacking from their half. Way easier than passing from the back and get pressed by the opposition forwards. And more safer especially against teams like Liverpool.
Herrera is now our holding DM if Carrick is not playing, not Fellaini.