Real Madrid coach Carlo Ancelotti has confirmed a knee injury for Eder Militao.
The Brazil defender broke down in victory at Athletic Bilbao.
Ancelotti said: He sprained his knee.
"It doesn't look good and we will assess it in the next few hours. Hopefully it's nothing serious. We're concerned and we're not ruling anything out."
On veteran pair Luka Modric and Toni Kroos, he added: They're part of a squad that has a lot of quality. I can't say that they're going to be substitutes. They're very important players. I've chosen this line-up today, but I might change it next week."
