Challenge? Certainly, but with (as you say) our injury list, I truly can't see us winning it, alongside maintaining our position in the PL and hoping to progress further in Europe.
It's not a 'teams like Brighton' mentality, just (imho) a grasp on reality.
I'm loathe to say it, but I'm really not fussed about the FA Cup this year. Hell, we're not going to win it, anyway, and we have enough on our plate as it is. There will always be other years to focus upon it.