During a typically eventful press conference with the Portuguese on Friday, the two-time Champions League winner was forced to dismiss reports that his relationship with his first-choice goalkeeper has completely broken down this season.
"There is no story with Casillas," he told reporters in the Spanish capital. "I have no problems with him."
Mourinho was then asked to address speculation that he is considering leaving the Santiago Bernabeu at the end of the season to take charge of big-spending City.
"I have no need to talk about my continuity," the former Inter boss declared. "I have two years left on my contract and have never said I will not stay."
Turning his attention to Madrid's recent media blackout, Mourinho admitted to being left bemused by the controversy caused by the club's refusal to speak to the press in the wake of their draw with Villarreal on March 21.
"After the Champions League semi-final against Barcelona last season, we opened our hearts and we were killed for it. In the Copa del Rey, as well," he argued.
"In Villarreal, we all decided not to talk about the game to avoid being sanctioned. We did not like [what happened] but we went away quietly, without creating controversy.
"We thought we were doing something positive and we were criticised for it.
"So then, the problem is not ours, but yours [the media]. Now we cannot be accused of generating pressure or creating controversy."
Mourinho was also asked to comment on Zinedine Zidane's recent revelation that he would like to pursue a career in coaching but he would only say: "You'll have to ask him about it."
Madrid return to Primera Division action after their midweek Champions League win over APOEL with a trip to Pamplona on Saturday to take on Osasuna.
Starting in March and continuing for 10 weeks, Goal.com is publishing exclusive extracts from Luca Caioli's new book, Ronaldo: The Obsession for Perfection. The second extract, published on Friday, looks at how Cristiano earned his 'cry-baby' nickname. Don't miss it!