Real Madrid defender Marcelo has reportedly emerged as a doubt for El Clasico after picking up a hamstring injury in Tuesday's Champions League clash against Paris Saint-Germain.

The Brazilian had to be withdrawn in the first half of the Group A match, which Los Blancos won courtesy of a 35th-minute effort from Marcelo's replacement, Nacho.

According to Marca, the substitution was more of a precaution, but the left-back will undergo scans this week to determine the extent of the damage.

If a tear is shown then the experienced full-back would be a major doubt for the clash with Barcelona on November 21.

Real Madrid booked their spot in the knockout stage of the Champions League with Tuesday's win.