Cristiano Ronaldo has been left out of the Real Madrid squad to face cross-town rivals Atletico Madrid in their La Liga game Saturday.

The Portuguese superstar picked up a minor knock in the 4-1 defeat to Borussia Dortmund in the Champions League semifinal first leg Wednesday, and Jose Mourinho has decided not to risk his best player for the Madrid Derby, ahead of the second leg against Dortmund.

"Before the match with Borussia Dortmund he had physical problems and will not be in the squad," Real assistant manager Aitor Karanka said of Ronaldo's exclusion. "He has not trained today (Friday). He has a muscular problem and can't play but we believe he'll be ready for Tuesday."

Real will also be without injured duo Marcelo and Alvaro Arbeloa, while Iker Casillas is again set to be left on the bench.

"Marcelo will not be there, who is longer term, nor Arbeloa, who did not finish training with the group," Karanka added. "The 11 that we think are the best to win tomorrow (Saturday) will play. Diego Lopez was the best in Germany. That choice is clear and you will see the rest of the team tomorrow."

Real Madrid are currently 13 points behind Barcelona, and can lose the title to their biggest rivals if they go down to Atletico, and if Barca win their match against Athletic Bilbao. Atletico will be motivated to pick up all three points, as a win will see them go level on points with Real.

"The match against Atletico is of the utmost importance to us because we are playing against our city rivals and our main competition for second place," Karanka said. "The best way to go into Tuesday's (Champions League) match at the Bernabeu is with a win at the Calderon and to distance ourselves from this bad moment as soon as possible.

"The best motivation is winning the matches before and we have to go there with the intention of winning and distancing ourselves in terms of points. We have to be at 120 percent and play with the same intensity as them.

"It will difficult because they're having an almost perfect year at home, because of their fans and the desire they have to beat us because it is a long time since they've done so."

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Expected lineups: Atletico Madrid: Courtois; Juanfran, Miranda, Godin, Luis; Garcia, Gabi, Suarez, Koke; Costa; Falcao.

Real Madrid: Diego Lopez; Nacho, Albiol, Carvalho, Coentrao; Essien, Modric; Di Maria, Kaka, Callejon; Benzema.

Prediction: 2-2