But Casillas told Canal+: "When we talk with the president it is for the dressing room. We were not talking about Mourinho. For me, Mourinho was one of the best coaches that I've had. He was daring, he had character. Then it came out that we had pressed the club."
The goalkeeper admits he also felt "isolated" from Perez when he found himself on the outer of the first team.
"It was worrying, I felt isolated," he recalled.
For the big stories and the banter follow us on Twitter: @tribalfootball