Spain coach Julen Lopetegui has dropped Chelsea striker Alvaro Morata over his poor form.
Marca says Morata has been left out the squad due to a drop in form and also his recent injuries.
Spain travel to Germany on Friday before heading back to Madrid to host Argentina on Tuesday in two international friendlies.
Morata, 25, has made 39 appearances for the Blues this season but has only scored once in 2018.
"Of course Morata has a lot of possibilities to go to the World Cup and he knows it," Lopetegui said. "He has to show these months the player he is inside."