Manchester City striker Sergio Aguero expects to be out for a month after sustaining a hamstring injury on international duty.
The 27-year-old was stretchered off 24 minutes into Argentina's 2-0 World Cup qualifying defeat to Ecuador on Thursday and now looks set to miss the Manchester derby on October 25.
Aguero underwent tests in his homeland on Friday and, upon leaving the clinic, told reporters: "I think I'm going to be out for a month."
The forward, who scored five goals in a 6-1 Premier League demolition of Newcastle United last weekend, is also likely to miss matches against AFC Bournemouth, Sevilla (home and away), Norwich City, Crystal Palace and Aston Villa over the coming weeks.
In a further blow for City, David Silva limped off during the first half of Spain's Euro 2016 qualifier against Luxembourg on Friday with what appeared to be an ankle injury.
Silva was fouled by Lars Gerson after just six minutes and, despite attempting to continue, had to be replaced by Juan Mata.
