Thibaut Courtois was hit in the adductors on Sunday during the warm-up before the defeat of the Madrid club in Mallorca (1-0).
Benzema injured his thigh last week during a La Liga match against Valencia (2-0 victory). Carlo Ancelotti rested him this weekend but had indicated that he would be available for the Club World Cup.
At 35, the 2022 Ballon d’Or is going through a season complicated by injuries, which notably deprived him of participation in the World Cup in Qatar.
Eden Hazard, Eder Militao, Ferland Mendy and Lucas Vazquez, also victims of physical problems, do not appear on the list released on Monday.
Real Madrid, four-time winners of the Club World Cup, enter the fray on Wednesday against the Egyptians of Al Ahly, before a possible final on Saturday against the winner of the match between the Brazilians of Flamengo and the Saudis of Al-Hilal.