Morata has been assessed by Spanish medics but Chelsea are taking a thorough look at him too.
Meanwhile the player has posted a message on social media hinting he's desperate to return for the club's next game.
Here, Starsport round-up the latest situation.
Morata was assessed by medical staff of the Spain national team earlier this week.
They gave the player and MRI scan at the Sanitas University Hospital of La Moraleja in Madrid and diagnosed a grade II myofascial injury in the hamstring muscles (hamstring tear).
They said the injury would likely rule him out for up to six weeks.
The Blues will make their own assessment on the player this week.
He's now back to the club's Cobham training base after being excused from Spain duty due to the injury.
An update on how long Morata will be out for is expected shortly.
Morata appears to have the first game after the international break on the mind.
Chelsea head to Crystal Palace on October 14 - and Morata wants to play.
On Instagram yesterday, he wrote: "I have no time to lose! Working hard towards recovery! Crystal Palace."
He later edited the post to read: "I have no time to lose! Working hard towards recovery!"
Assuming Morata's injury takes a month to recover from he'll miss Chelsea's Premier League clashes away at Palace, home to Watford and away to Bournemouth as well as both Champions League ties with Roma and the EL Cup clash with Everton at Stamford Bridge.
If the injury recovery time extends into November he’ll miss the home fixture with Manchester United on November 5.
Following that two-week break there is a two-week international break, where Spain are likely to be playing friendlies rather than World Cup qualifying play-offs.
Spain are three points ahead of Italy in Group G with two matches remaining.
The 2010 World Cup winners are expected to seal top spot, with games against Albania and Israel to come.
Antonio Conte has so far shown he doesn't trust Michy Batshuayi when his leading striker is out.
Eden Hazard played up top last term when Diego Costa was missing, with the Belgian striker looking on from the bench.
Conte could do the same again, but Batshuayi says he's up to the task.
He said: “I know Conte has confidence in me. Otherwise, he would have let me leave during the summer.
"It's a chance for me. If I'm called on, I want to be ready and efficient. I have to stay really focused."
