Manchester City defender Vincent Kompany has been forced off after 20 minutes of today's derby match through injury.
Kolo Toure replaced the Belgian international, who looked in some discomfort as he left the field.
Toure will partner Matija Nastasic in an unfamiliar centre-back pairing for Robeto Mancini's side.
City trail 2-0 at the Etihad in the early stages thanks to a brace from Wayne Rooney.