Spain coach Julen Lopetegui said he has the squad he wants to take to the World Cup in mind but is leaving the door open for Bayern Munich midfielder Javi Martinez and other players.
Martinez, who won the 2010 World Cup and Euro 2012 with Spain, has not played under Lopetegui since the coach replaced Vicente del Bosque in 2016. He was part of the 2014 World Cup squad but missed Euro 2016 through injury.
He told ESPN FC's Raphael Honigstein last week that he is in the dark as to why Lopetegui has overlooked him.
"I have the list for the World Cup outlined but it's not closed," Lopetegui told Radio Marca. "There are players that have options although they have not made this squad. Neither in the case of Javi Martinez nor any other do I want to close the door. It's obvious that there are players that have possibilities."
One player in the squad is Isco despite the midfielder having played just one full game in his last eight appearances for Real Madrid.
Isco did start in Friday's 1-1 international friendly draw at Germany and was praised for his performance.
Lopetegui is hopeful Isco, who is expected to start Tuesday's international friendly against Argentina in Madrid, will have a starring role for Real Madrid in the coming months.
"Isco is an important player in the national team and it's also important that he delivers [for Spain]," Lopetegui said.
Asked about why Isco is not a starter at Madrid, Lopetegui said: "I will never judge a colleague [in Zinedine Zidane]."
In September, Isco signed a new contract with Madrid until June 2022.
The 25-year-old was instrumental in Madrid winning La Liga and the Champions League last season, scoring the winning goal against Atletico Madrid that booked his club's place in the Champions League final.
He was also pivotal in the key away wins over Sporting Gijon and Deportivo La Coruna that set Madrid up to win the La Liga title.