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Jose Mourinho's fallout with the Real Madrid dressing room has been laid bare in the new documentary about his career.

Mourinho returned to the Bernabeu this summer, 13 years after his turbulent first stint came to a close.

During that three-year spell, the legendary Portuguese boss clashed with several senior players, including club captain Iker Casillas.

And in a new Netflix documentary Mourinho, released earlier this week, further light has been shed on just what happened.

In the show, Mourinho was asked about his relationship with Casillas, who he had originally labelled as the 'captain and best player' upon his arrival.

'Mentally, they were in a very bad place,' he said of Real's squad. 'The first thing he (Casillas) told me was: "I've come to ask for more vacation time for the national team players".

Jose Mourinho and Iker Casillas have opened up on how their relationship fell apart

Mourinho's fallout with Casillas also impacted his relationship with Real star Cristiano Ronaldo

'In the second conversation, he asked me to delay training by an hour because there was a lot of traffic in Madrid at the time I wanted to start the session.

'In the third, he told me they didn't want to go to the hotel, that they preferred to see each other on match day and go directly to the stadium.'

Following these conversations, Mourinho added: 'I realised they were being spoiled.'

From this moment, Mourinho's relationship with Casillas continued to deteriorate, with one particular flashpoint coming when the keeper called Xavi to ease tensions between the Spanish players at Real Madrid and Barcelona.

This came at a time when the El Clasico rivalry was particularly fierce while Mourinho and Pep Guardiola were in charge of either team.

'This is a Barcelona-Real Madrid match,' Mourinho added. 'When you're with the national team, you can kiss each other twice, but not now. This is war.

'There are things I don't accept and never will. When someone doesn't respect me, it becomes a problem.'

Explaining the reasons for the call, Casillas, who was interviewed for the documentary, explained: 'That situation was complicated because you were captain of Real Madrid and captain of the Spanish national team.

'You were facing team-mates who were your enemies on the football field, but then they were your team-mates on the national team. I didn't like seeing that and I told the manager.'

Reflecting how their conflict erupted, with Mourinho later dropping Casillas, former Real midfielder Sami Khedira added: 'Iker was a Real Madrid legend, beloved by the fans.

'Mourinho benched him and wouldn't speak to him, spoke ill of him in the media... the dressing room became a hellhole.

'After that, the relationship between Jose and many players, like Cristiano Ronaldo and the Spanish players, broke down. And those players were very important to the atmosphere in the dressing room, which became poisoned.'

Mourinho also later suspected Casillas was a dressing room 'mole', leaking line-ups, tactics and internal secrets to the media.

Mourinho is now back at Real and a documentary about his career was released this week

Speaking at the end of that first spell, Mourinho had opened up on why it had come to an end.

'I think the players had grown tired of me as a leader, and I of them too,' he said. 'I was fed up with them as well, not just them with me.

'I was fed up with the players and the press. I wanted to leave. I felt I was finished.'