Isco was outstanding for victory at Sporting Gijon.
But Zidane admits: "He's ready, like everyone. That's the most important thing for me.
"Tomorrow we'll decide who plays and how we're going to play. It's coincidence, but due to rotations, he's not played much in the Champions League. We have a lot of important games and we'll see what we do tomorrow. I have decided who plays but I'll not say.
"Everyone is doing phenomenally well, but I have to choose and I'm glad that everyone is at this level. It's better to have this problem when having to choose the team."