Villarreal holding midfielder Rodrigo "Rodri" Hernandez also earned a first call-up, making the leap from the under-21s to the first team.
Alonso never represented Spain at under-21 level but his performances for Chelsea in a wing back position have caught Lopetegui's eye and he now has the chance to stake his claim to a place in the final squad in Russian Federation.
"But he's not out of our thoughts and he has his chances to go to the World Cup".
"Diego is back with us because he has returned to play but this does not guarantee him a [World Cup] place", Lopetegui said.
Antonio Conte has declined to show Gary Cahill and Álvaro Morata a great deal of sympathy after they were omitted from their respective global squads, with the Chelsea manager making clear the only way for them to prove they deserve to go to the World Cup is by working hard for their club.More news: American Idol Auditions Continue with High Notes and Tears
Costa had not been called up in more than nine months because he couldn't play with Atletico until the team's transfer ban from Federation Internationale de Football Association ended in January. "They'll all be competing for their spots".
He was quoted as saying by L'Equipe: "Admittedly, Alvaro Morata has not scored for a long time, but he is our team-mate and when the team loses, we all lose together. Morata I am sure will have a great end to the season and will have a good chance of going to the World Cup". I am only focused on our upcoming game and I want to have players that are in good physical shape. "This list is down to form, injuries and us wanting to see other players".
The Chelsea boss refused to make too much of a comment on his recent displays but insisted he is not bothered if he or Cahill make the final World Cup squads.
Also returning to the squad is Chelsea centre-back Cesar Azpilicueta, who was left out of Spain's previous two friendlies in November.
"We are looking to get more information about players".