According to Julien Maynard, the 34-year-old has been ruled out of the El Clasico due to a calf injury he sustained during the second half of the 3-0 victory over Mallorca last weekend. Benzema's absence is likely to be a massive blow for Los Blancos, who have been heavily reliant on his goalscoring ability this season.
Benzema has had a phenomenal campaign, scoring 32 goals and providing ten assists in 34 appearances across competitions. He scored a brace in Madrid's 3-0 victory over Mallorca last weekend.
The Frenchman single-handedly led Madrid to the quarter-finals of the UEFA Champions League. He scored a 17-minute hat-trick against PSG in the second leg of the Round of 16 last week after Madrid trailed 0-2 on aggregate with 29 minutes to go. Los Blancos eventually earned a 3-2 aggregate win to book a quarter-final clash with holders Chelsea.
Benzema has also formed a formidable partnership with Brazilian sensation Vinicius Jr. and Spanish winger Marco Asensio in attack this season. Vinicius has scored 17 goals and provided 14 assists in 38 appearances, while Asensio has contributed ten goals in 32 games.
Benzema's absence could be a huge loss against a Barcelona side unbeaten in 11 games across competitions. Xavi's side has scored four goals in four of their last five games in all competitions. The Blaugrana have won four and drawn one of their last five La Liga games.
Barcelona hold the upper hand over Real Madrid heading into Sunday's El Clasico
Real Madrid have no adequate replacement for Karim Benzema. Serbian striker Luka Jovic has been in dismal form this season, scoring just once in 17 appearances. Mariano Diaz has been on the fringes of the squad, making only six appearances.
Barcelona, meanwhile, possess many forwards at the top of their game. Pierre-Emerick Aubameyang has scored five goals in six La Liga games since arriving on a free transfer from Arsenal in January.
Ousmane Dembele has scored once and provided five assists in his last four league games. Adama Traore, who joined Barcelona on loan from Wolves in January, has contributed four assists in nine appearances.