The Frenchman has been named in the Blancos' 20-man party for the clash with the Catalans, despite coach Jose Mourinho initially harbouring doubts over his striker's participation
The French striker was taken off during the match against Celta Vigo on Wednesday after he sprained his ankle, but he has recovered in time to take his place in the Blancos' 20-man party.
However, Raphael Varane misses out after failing to shake off a knock in the Copa del Rey tie, but Fabio Coentrao returns following a two-game absence while Angel Di Maria is similarly in contention to start.
Madrid boss Jose Mourinho previously intimated that Benzema was unlikely to feature against the Catalans, telling reporters at a press conference: "I don't think Benzema will play tomorrow.
"For me, if he has picked up an injury of any kind he should not be fit to play two days later."
The Blancos' boss went onto praise new Espanyol coach Javier Aguirre for the style of football he plays and the work ethic that he brings to his teams.
"Espanyol have a coach that I really get on with. His teams always play attractive football and have a top work-rate," Mourinho said.
"I think that Aguirre will build on the foundations that the last coach put in place and start getting some good results very soon."
Real Madrid squad to face Espanyol: Casillas, Adan, Jesus; Ramos, Pepe, Carvalho, Arbeloa, Coentrao, Nacho; Alonso, Khedira, Ozil, Essien, Modric, Callejon, Di Maria, Kaka; Ronaldo, Benzema, Morata.