Julen Lopetegui lasted just 14 matches as Real Madrid manager.
The 52-year-old coach - who was fired by Spain on the eve of the 2018 World Cup - was officially sacked on Monday night following the 5-1 drubbing at the hands of Barcelona.
"Every single one of us has been disastrous tonight," said Casemiro after Sunday's El Clasico defeat.
"We didn't give the best image of ourselves. It's happened too often this season. We didn't play well enough.
"We can't blame the manager. The players are fighting for everything on the pitch, but the result is different."
Zinedine Zidane and Cristiano Ronaldo quit Real Madrid in the summer and the club have struggled badly in the early stages of the 2018/19 season.
They currently lie ninth in the table, having failed to register a win in each of their last five La Liga outings.
Real Madrid released a statement on Monday night, thanking Lopetegui for his efforts and wishing him luck for the future.
However, plenty of fans have criticised the board for one "extremely tasteless" sentence.
"The board considers there to be a large disparity between the quality within the Real Madrid squad, which boasts eight nominees for the next Ballon d'Or award - an unprecedented number in the club's history - and the team's results to date."
Not exactly classy.
Referring the eight Ballon d'Or nominees, Florentino Perez is clearly trying to absolve the players and the board by putting all the blame on Lopetegui.
Whoever takes over from the former Spain boss has a massive task to turn Real Madrid's fortunes around.
Former Real Madrid Castilla boss Santiago Solari was appointed as the new interim manager.
Los Blancos visit Melilla in the Copa del Rey on Wednesday night before hosting Real Valladolid in La Liga on Saturday afternoon.
What do you think of the "unnecessarily scathing" Real Madrid statement? Let us know what you think by leaving a comment below.