Chelsea will make their own assessment of Alvaro Morata's hamstring injury later this week after the striker was ruled out of international duty with Spain.

The 24-year-old was substituted after 35 minutes of Chelsea's 1-0 loss to Manchester City in the Premier League last Saturday.

Chelsea head coach Antonio Conte expressed hope Morata's departure had come prior to serious injury to his left hamstring.

But the results of a medical assessment by the Spanish Football Federation suggest Morata could be out for around four weeks. No time frame for his recovery has been given.

Morata met up with Spain on Sunday, where an MRI scan at the Sanitas University Hospital of La Moraleja in Madrid diagnosed "a grade II myofascial injury in the hamstring muscles", the Spanish Football Federation said.

He was immediately ruled out of Spain's World Cup qualifiers with Albania and Israel.

Chelsea will conduct their own tests once the striker returns from Spain, where he has other commitments.

The Blues, six points behind Premier League leaders City, next play on October 14 at Crystal Palace in the first of six games in 18 days.

Morata has scored seven goals since signing for £58million from Real Madrid as a direct replacement for Diego Costa, now at Atletico Madrid.

Alvaro Morata was forced off in the first half against City (Getty)

His possible absence will give Michy Batshuayi an opportunity, if Conte selects the Belgian who has netted five times this season, including the winner at Atletico last week.

Batshuayi was overlooked against City as Willian was sent on as a substitute for Morata, while Conte has also spoken of using Eden Hazard as a 'false' nine.

A month-long absence for Morata could impact Chelsea's Champions League hopes - two of the six games before the end of October are against Roma - but the other matches are more favourable.