Madrid are 11 points behind the Camp Nou club, who have not lost in La Liga this season.
If Zinedine Zidane’s men lose this weekend, they can as well forget about defending their LaLiga title this season.
Cristiano Ronaldo is already a doubt for the game, after missing full training for two consecutive days.
Real took the honours when the teams met in the Supercopa, with Ronaldo scoring in the 3-1 first-leg win before being sent off.
Kick off is 1pm.
Real Madrid vs Barcelona