Keylor Navas doubtful as Real Madrid face Las Palmas

Madrid: Spanish giants Real Madrid could be without their key goalkeeper Keylor Navas when they face the struggling Las Palmas in La Liga on Saturday.

The Costa Rican has been in outstanding form this season but is currently struggling to recover from a muscle strain which he picked up in training, reports Xinhua.

With a massive Champions League game at home with French side Paris Saint Germain coming up next week, Madrid coach Rafael Benitez is unlikely to risk him, which could mean a debut for Kiko Casilla.

Casilla, Real Madrid's summer signing from Espanyol, has had to warm the bench since his arrival but could now finally get his chance.

Benitez confirmed in an interview on Spanish radio on Thursday night that forward James Rodriguez remains sidelined with a thigh injury, while defender Dani Carvajal is still trying to recover from his knee problems.

Elsewhere the side more or less picks itself, and Benitez has an embarrassment of riches to choose from, especially considering the form of winger, Lucas Vazquez, who has taken full advantage of the chances he has had due to the injuries suffered by attackers Gareth Bale and Karim Benzema.

Casimiro has also shone in a central midfield role, a position which the Brazilian has begun to make his own, with his high work-rate and ability to win the ball in central midfield very much to Benitez's liking. His presence may allow Luka Modric or Tony Kroos to rest on Saturday.

Las Palmas travel to Madrid rooted in the relegation zone, but will take heart that they were able to draw their first game under coach Quique Setien last Sunday.

Quique Setien replaced Paco Herrera as the coach recently, but will have taken note of their good display against champions FC Barcelona, where they only lost 1-2.

Setien said his side will "need to show personality," even if they do that, however, it is likely to be tough against the league leaders.