Chelsea have been dealt a major blow after the Spanish Football Federation claimed striker Ãlvaro Morata has suffered a grade two hamstring injury that could rule him out for two months.
The club's record signing Morata was forced off in the 35th minute of Chelsea's defeat to Manchester City with an injury to his left hamstring.
Manager Antonio Conte admitted he took a risk over the fitness of Morata by starting him against City, but had suggested the Spaniard's injury was not serious.
But in confirming that Morata had pulled out of the Spain squad for the games against Albania and Israel, the Spanish Federation revealed the 24-year-old had undergone an MRI scant that revealed a grade two grade II myofascial injury in the hamstring, according to the Telegraph.
Medical experts claim that a grade two hamstring injury can sideline a player for anywhere between six to eight weeks.
The Spain international, who moved to Stamford Bridge from Real Madrid during the summer for Â£70m, was withdrawn from Spain's World Cup Qualifiers against Albania on Friday and Israel on Monday because of the problem.
Since joining the London club this summer, Morata has scored seven goals for Chelsea and quickly established himself as one of the club's key players.
Tellingly, Conte opted to replace Morata with Willian against City which only increased theories that he does not trust Michy Batshuayi in big games.
Chelsea travel to Crystal Palace after the international break, which Morata appears likely to miss, and also face Roma twice in the Champions League during October, as per Sky Sports.
Should Morata be ruled out for any length of time, then more questions will be asked over why Chelsea did not sign more forward cover during the summer transfer window.
Conte wanted to bring in Fernando Llorente from Swansea City, but Chelsea were beaten to his signature by Tottenham Hotspur and Tammy Abraham was allowed to join the Welsh club on loan.
Chelsea last week confirmed that last season's top scorer Diego Costa had officially returned to AtlÃ©tico Madrid on an initial loan that will eventually become a Â£57.5m permanent deal.