Manchester City striker Sergio Aguero faces missing the derby against Manchester United due to a hamstring injury.

The 27-year-old left the field on a stretcher early in Argentina's defeat by Ecuador on Thursday night and national team officials have subsequently revealed he suffered damage to the back of his thigh.

Aguero told reporters in his home country on Friday: "I think I'll be a month without playing."

That would rule him out of the derby against United at Old Trafford on October 25 and the Champions League tie at home to Sevilla that precedes it.

Premier League leaders Manchester City face Bournemouth after the international break before facing rivals United in the derby.