In that case it has to be Sanchez. It's a question of numbers. There is only 2 proper strikers. One of whom is injured and wont be back until end of February, and probably won't be match sharp until end of march, the other has been blowing hot and cold. You could try playing sterling at CF but you will miss him on the wing. So I think Sanchez is needed.
At CB there is cover. You have stones Otamendi and Kompany and Tosin. I'd say even Danilo could do a job there. Mangala may not be first choice but he has played well enough when called upon.