Real Madrid caretaker coach Santiago Solari labelled Isco "special", but said he was unwilling to rush the midfielder.
Isco, 26, underwent an operation to treat appendicitis in September and has not started any of Madrid's past three games – all wins since Solari took charge.
Solari praised the Spain international but said the playmaker had work to do to get back to his best.
"We know Isco's quality and how special he is. He is training to get back to peak fitness," he told a news conference on Saturday.
"He had a delicate operation and it's not easy to come out of that, but he is training with the group.
Next target: November 8, 2018
"All of us who have been footballers know that you have to keep training to get back to your best."
Madrid have scored 11 goals and are yet to concede in Solari's three matches in charge, and they visit Celta Vigo in LaLiga on Sunday.
