"Carvajal is a very important figure in our dressing room," De la Fuente told reporters on Wednesday.
"I actually spoke with him yesterday, so I’m aware of what’s going on. He doesn’t have a specific injury, nothing serious, but he needs time to get back to his usual level.
"We’ll see in the remaining matches whether he truly gets the opportunity and delivers the performances."
De la Fuente added that Carvajal, who made just one appearance for Spain in 2025, would understand if he was left out of the squad for the World Cup, which is being held in the United States, Canada and Mexico from June 11th to July 19th.
Carvajal, 34, is approaching the final weeks of his contract with Real and has struggled for game time this season amid competition from Trent Alexander-Arnold.
Spain begin their World Cup campaign against Cape Verde on June 15th and also face Saudi Arabia and Uruguay in Group H.