The Brazil international will miss Saturday's Primera Division encounter after scans showed on Friday that he is suffering from arthritis in his left knee
Real Madrid have confirmed that Marcelo is suffering from traumatic arthritis in his left knee and will miss this weekend's Liga match against Real Sociedad.
The Brazil international picked up a knock in Friday's training session ahead of Saturday's visit of la Real and the 25-year-old now faces a spell on the sidelines.
A statement on Madrid's official website reads: "Following examinations and scans carried out today Marcelo at Sanitas-La Moraleja hospital, he has been diagnosed with traumatic arthritis in the left knee."
Head coach Carlo Ancelotti's men sit six points adrift of league leaders Barcelona ahead of the clash the Basque side and the Italian is expecting a difficult challenge.
"Real Sociedad are a good team with a good attitude," he said.
"They're very dynamic and have fast players. It won’t be an easy match. They already proved against Manchester United that they can play major games and it's a really good test for us because we need to play well and with intensity."
Marcelo has made eight Liga appearances so far this term.