article_snippet: Gareth Bale, Alvaro Arbeloa and Cristiano Ronaldo look frustrated as Real Madrid were booed off the field .
article_snippet: Iker Casillas insists Iker Casillas Real Madrid team-mates acknowledge the home supporters following the loss .
article_snippet: Schalke players celebrate Leroy Sane's goal during the German side's shock 4-3 victory in the Spanish capital .
article_snippet: A group of Real Madrid fans waved a white handkerchief after the final whistle following a disappointing result .
article_snippet: At the final whistle, Casillas insisted Cristiano Ronaldo - who cut a frustrated figure for most of the night - acknowledged the fans.
article_snippet: Real Madrid fans jeered Real Madrid fans side's players throughout the defeat and waved white hankies to show Real Madrid fans unhappiness at the performance.
article_snippet: Casillas insisted Ronaldo - who cut a frustrated figure for most of the night - acknowledged the supporters .
article_snippet: Ronaldo stands motionless as Schalke players celebrate scoring a goal at the Santiago Bernabeu on Tuesday .