Ronald Koeman has announced that Ansu Fati is a doubt for Wednesday's LaLiga game against Rayo Vallevano.
Ansu, 18, was named in the squad for the game after training on Tuesday but a final decision on his involvement has not yet been made.
"Ansu had some pain (during the Clasico vs. Real Madrid) but not related to the injury he had," Koeman said in a press conference.
"He's still a doubt for Rayo. He's in the squad but we will make a decision on Wednesday regarding if he travels with us or not."
In contrast, Koeman expressed optimism regarding Sergio Aguero, who he suggested could start the game having now made three substitute appearances.
"He's still not ready for 90 minutes but he is in condition to start the game or to play the second half," the Dutch coach added.