Problem is that Cazorla is not on his game. Its funny, but I was happier knowing we had Vermaelen to come on than I would have been with any MF substitution.
I am not buying Cazorla is off form. Have you heard what Henry said a few days ago? When there were so many players going forward eventually one or two has to stay deeper. In our case, it is Cazorla who makes way for Ozil, Ramsey and Jack to roam freely on the pitch.