The former Madrid supremo feels the current Chelsea manager was out of his depth at the Santiago Bernabeu and is full of praise for Carlo Ancelotti
The Portuguese coach endured three years full of incidents and conflicts at the Spanish side after joining them from Inter in the summer of 2010.
Mourinho eventually left Madrid for a return to Chelsea after the 2012-13 campaign and Calderon believes his struggles in the Spanish capital were down to the enormous pressure.
“To be a coach of Real Madrid is really, really difficult,” Calderon told BBC World Service.
“See what happened to Mourinho. He is someone who is used to coping with pressure and he couldn’t at Madrid.
“When Mourinho left, things were in a really bad situation. He had to leave the club after three years of a lot of problems, a lot of confrontations.”
Mourinho guided Madrid to the Liga title in 2011-12 and the Copa del Rey in 2010-11, but failed to steer them to Champions League glory, unlike his successor Carlo Ancelotti, and Calderon feels the Italian has done a great job since replacing Mourinho, although he feels he could be on his way out as well in the not too distant future.
“To be here more than two, three years is really a big task. I think he has done a very good job, not only because he won the Champions League but because things are calm, relaxed and everything is smooth.
“I have read Joachim Low is one coach we would like but it is always rumour and we will have the rumours until the next five months when it is decided whether definitely Ancelotti will be here.”