We all know that as soon as we lose a couple of first team players the whole thing falls apart. Whoever replaces Benitez will have to deal with the same shite.
I can see us sacking him just before DCL comes back and just as Doucoure and Mina are getting their match sharpness back, which the new manager will benefit from. Before it all goes to shit as soon as they're injured again.
Having no backup left back and not signing a right back is not Benitez's fault.
And to be fair to Benitez he has identified the clubs injury issues as a major problem and is trying to fix it.