The Spanish No. 1 came through the ranks at the club, and, similar to Raul before him, he has a God-like status in Madrid. To fall out with him is to fall out with every Madridista, which has happened with Mourinho this term.
A mixture of injuries and Mourinho's insistence that he remain benched has meant he hasn't featured for Real since late January.
With Mourinho's departure now confirmed, it seems there's a light at the end of the tunnel for Casillas as he bids for the nightmare to end, or will this season have proved his last for Los Blancos?
Contract Situation: As you would imagine for one of the club's proudest sons, Real Madrid have Casillas tied down to a long-term deal, His contract runs through to June 2017, when he will be aged 36.
Career Stops: Real Madrid (1999-current)
Current Campaign: La Liga: 19 games, eight clean sheets; Copa del Rey: three games, two clean sheets; Spanish Super Cup: two games; Champions League: five games
Scouting Guide: Despite being in his early 30s, Casillas remains as agile as he was when Europe first caught a glimpse of the talented stopper in his teenage years when he became Real's No. 1.
He hasn't given up the jersey until this season for good reason, either. He is athletic and reads the game excellently, proving a commanding presence in the box.
Despite his 6'1" frame—relatively short for a goalkeeper in the modern era—he is rarely intimidated. Ahead of Mourinho dropping him earlier this term, he did admittedly have a drop in form, but make no mistake, even at his worst, Casillas is a fine goalkeeper.
Now that Mourinho is leaving the Bernabeu, it should be a case of business as usual for Casillas. Be truthful, can we really imagine him leaving Real Madrid?
Whoever replaces the Portuguese manager will need to win over the dressing room instantly, and what better ally to have than club captain Casillas?
In early May, Sky Sports reported that Casillas had no intention of leaving his boyhood club.