I have a feeling I will be slated for what i'm about to suggest but...
I think Idrissa Gueye of would be a good buy. If the club sell Fernando,Delph and let Toure leave on a free which I think they should do because. The club will have room for a few new ones, and I strongly believe they need fresh legs in that area, it's one of the weakest positions in City. If not for the first team Idrissa Gueye would make a fantastic backup option far better then what's currently available. He has so many attributes that suit Peps style of play.