You mean in terms of us doing your lot a favour by beating Arsenal?
I'm quietly confident about this one -- we always manage to beat Arsenal, even when we're crap (and Jose's record against Wenger is excellent). I do think that Lingard or Young will play on the wing with one of Rashford/Martial up front. I just get the impression that Mourinho doesn't trust both youngsters to start in the same XI in such a big game. I'm guessing we'll start with something like this:
------------de Gea
Valencia---Jones--Rojo---Blind
-------------Carrick
--------Herrera---Pogba
Mata-------Rashford-----Lingard
The understanding that Lingard and Pogba seem to have works in Jesse's favour. Young is played solely for defensive capabilities these days, and as a pure defensive winger, he's our best bet. But Lingard is more of a hybrid type -- defends from the front, but offers a threat in attack as well. Jose likes him a lot, I think.
If Rooney is actually fit (doesn't seem to be the case), he'll probably start. And it's a tossup between Rashford/Martial, but with Marcus being more of an out and out CF, I think he'll get the nod (assuming both don't start together).