Pellegrini: Joe Hart could miss up to 1 month with calf issue

Following Manchester City's disappointing 1-0 home loss to arch-rival Manchester United, Manuel Pellegrini announced goalkeeper Joe Hart could be out for up to a month.

The England No. 1 was stretchered off after the hapless Martin Demichelis dispatched a shaky back pass. Hart injured himself while sliding in to prevent Anthony Martial from beating him to the ball.

Related: 3 things we learned as Rashford delivers Manchester derby victory for United

"I don't think muscle injuries will heal in one week. They normally need three or four weeks," Pellegrini said, also referring to the groin problem suffered by Raheem Sterling in the first half.

Despite the early estimations of his Chilean boss, the problem shrouds Hart's England involvement at Euro 2006 in serious doubt. It could leave Stoke City's Jack Butland and Southampton's Fraser Forster vying for a spot between the sticks this summer.

Sterling has been a regular for Roy Hodgson, too, and like Hart will be pulled from the England squad for the upcoming friendlies against Germany and the Netherlands.

City's hurtful derby defeat to United on Sunday has Pellegrini's side scrambling for qualification to the Champions League next season. Failure to do so could deal a severe blow to the ambitions under incoming manager Pep Guardiola.

International football is now on the agenda for most in the City squad, which will return to club action with a trip to Bournemouth on April 2.