The 31-year-old goalkeeper suffered a hand injury in his side's 1-1 Copa del Rey draw against Valencia on Jan. 23, forcing the signing of Diego Lopez, who has performed admirably in the club captain's absence.
Los Blancos assistant coach Aitor Karanka has now made it clear that the Spain international is raring to go again after getting the green light from the club's medical staff last month.
"He is at a high level again and has been included in the match squad," Karanka stated at a press conference. "He has shown his best on the training pitch this week and we are happy to have him back at this decisive stage of the season."
Casillas' inclusion in the match squad means that Lopez could start the Levante game on the bench, but the former Villarreal keeper is likely to reclaim his place for the trip to Galatasaray in their Champions League quarterfinal second leg on Tuesday.