Manchester City playmaker David Silva has been ruled out of Sunday's derby against Manchester United, manager Manuel Pellegrini has confirmed.
The Spain international suffered a knee injury during Wednesday's League Cup defeat to Newcastle United.
City boss Pellegrini has confirmed the Spaniard has suffered a knee ligament problem and could miss up to a month of action, ruling him out of the visit of Louis van Gaal's side.
Reports as to the extent of Silva's injury had been circulating since Wednesday's match, but this is the first time the club have confirmed the extent of his lay-off.
Silva has been some way short of his best form this season, but has still notched two goals and two assists in his nine Premier League appearances thus far.