Probably Carrick instead of Fellaini, considering he was fully rested today.
I don't think Carrick will be a regular under Mourinho.
I think he was just awarded a new contract cause Mourinho likes to have an experienced head around for the time being, someone who knows the dressing room and club while Jose gets used to the job. And lets face it, after losing Evra/Vidic/Rio/Giggs/Fletcher/etc, there isn't many of them around at United currently.
I'm sure Carrick will come on the odd time and cool the game off. Maybe start the odd game and play in the Cup matches but I can't see him as a nailed on starter. We have Pogba, Schneiderlin, Fellaini, Herrera and if he keeps him around, we have Schweinsteiger as well.
All of those are comfortably better options than Carrick in my opinion.
It's not like we're short of midfielders anymore and have to rely on an aging midfielder. A few seasons back, our only CMs were Carrick, Cleverley, Anderson and Fletcher. Back then, it was understandable. Now? No. We need to be giving game time to the likes of Schneiderlin. Maybe even Blind and Fosu Mensah in the CDM position aswell. There's just so much more exciting options right now. Putting Carrick in the middle of it all would just bring the look of the team down. He's past it and I can't really remember any standout performances from him recently.