Manchester City are preparing for the derby with crosstown rivals Manchester United without two of their best players.

Striker Sergio Aguero is expected to be out for at least six weeks with the hamstring injury he sustained on international duty with Argentina last week and will certainly miss the October 25 clash with the Red Devils at Old Trafford.

In further bad news for the current Premier League leaders, playmaker David Silva is set to be out for about two weeks with the ankle problem he sustained while playing for Spain.

Doctors from the Argentine and Spanish teams handed down the initial forecasts for Aguero and Silva and it has since been confirmed by City doctors, who have viewed the scans, that the pair will be sidelined for the timeframes already reported.

It is a massive blow for Manuel Pellegrini's side who rocketed back to the summit of the English top flight by emphatically beating Newcastle United 6-1 last time, with Aguero scoring five goals and Silva plugging he strings in midfield.

City return to Premier League action by welcoming Bournemouth to the Etihad Stadium on Saturday.