Roma sit second in their group with four points in two games. La Roja now lead Group G by three points ahead of Italy.
Morata, who has scored six goals in seven Premier League games for his new club, pulled up 10 minutes before half-time in the 1-0 defeat by Manchester City at Stamford Bridge on Saturday, complaining of discomfort in his left thigh.
Morata has netted seven goals in eight games under Antonio Conte in all competitions for the Blues.
"It's a muscular problem".
The doctor now in the next days has to check the situation, but I don't think he's available for the national team.
2 pilots killed in training jet crash in Tennessee, US Navy says
A US Navy spokesman had earlier announced a T-45 Jet was missing after it took off from Naval Air Station Meridian in Mississippi. Monroe County Sheriff's Office confirms they are responding to reports of a plane crash Sunday afternoon in Tellico Plains.
The Spanish football federation have confirmed after tests that Morata has suffered a grade two hamstring tear.
Morata was examined at a Madrid hospital after reporting for worldwide duty, and an MRI...
Chelsea will now monitor Morata's recovery and hope that he is fit to face Crystal Palace on October 14.
The injured trio have been replaced by 36-year-old Athletic Bilbao striker Aritz Aduriz, Real Sociedad full-back Alvaro Odriozola and Las Palmas midfielder Jonathan Viera.