Casemiro felt Real Madrid failed to turn up for the first half of their 3-0 loss at Sevilla but does not believe the result will have an impact upon Saturday's derby against Atletico Madrid.
Andre Silva bagged a brace inside 21 minutes and Wissam Ben Yedder added further punishment for Julen Lopetegui's men before the interval.
It meant a first LaLiga defeat of the season for Madrid, who failed to capitalise upon Barcelona's shock 2-1 loss at Leganes earlier on Wednesday.
"We gave away the first half," Casemiro told Movistar. "We did not play like we have played all season.
"[Sevilla] are a very difficult opponent and, if we give away 45 minutes, this happens."
Asked whether the reverse made the derby more difficult, the Brazil international added: "Each game is difficult. When playing the derby at home we have to get points. They are a great rival."
