After some unsavoury sniping between Mourinho and members of his squad in recent weeks, Perez made a rare foray into the limelight on Monday when he called for the club to be "united for the fans" as they prepare for this month's King's Cup final against city rivals Atletico Madrid and seek to secure second place in La Liga.
Mourinho raised eyebrows on Friday when he made a thinly veiled attack on goalkeeper Iker Casillas, whom he has dropped in favour of Diego Lopez, prompting club heavyweights Sergio Ramos and Pepe to speak out in support of their captain.
At a news conference on Tuesday previewing Wednesday's La Liga match at home to Malaga, he responded to compatriot Pepe's expression of support for Casillas, made after Saturday's 4-3 La Liga victory at home to Real Valladolid.
"You just have to be a normal person like me or like almost everyone in this room to know that we are talking about frustration," Mourinho said.
"His problem has a name: Raphael Varane. It's not easy for a man of 31 years, with status and history, to be trampled over by a kid of 19.
"But that's the law of life. On a sporting level Pepe's life has changed.
"I have no problem with him. I understand that it's not an easy situation but I have to try to be honest and I think that there are very few people who don't think that the future of Real Madrid in defence is Varane with Sergio Ramos."
"Let's see if you understand it once and for all, I am a football coach," Mourinho told reporters.
"They hired me to be a football coach and a football coach has certain responsibilities, one of which is to pick the team.
"I don't do it by flipping a coin. I do it after discussion and lengthy analysis of my decisions.
"For me, I like Diego Lopez better as a goalkeeper than Iker Casillas. I don't do it to harm anyone.
"I accept it if someone says that Casillas is better than Diego Lopez but you have to accept that I am the coach of Real Madrid."
