Since the current Chelsea boss left the Santiago Bernabeu in 2013, there have been a number of instances where the two have seemed far from friendly - most recently Mourinho suggested Ronaldo was partly to blame for Real Madrid's Champions League exit in 2011-12 at the hands of Bayern Munich due to his missed penalty.
Mourinho says he has not forgotten how influential Ronaldo was during the coach's reign in Spain, but was key to point out their days of working together and speaking regularly are over.
"The relationship between Ronaldo and myself is non-existent," Mourinho told TV1. "He plays for Real Madrid, I'm the Chelsea manager.
"You would not find us hanging around together. The relationship does not exist, but the remembrance of his impact does. I have to remind myself that he is a goal machine who helped me become a Liga champion, win the Copa del Rey and the Supercopa.
"I try to keep the best memories of Cristiano Ronaldo with me and I wish him all the best in his career - especially with Portugal, but also with his club."
The duo have not gone head-to-head in competitive football since Mourinho left the Madrid hotseat a little over a year ago, but Chelsea and Real Madrid are two of the three favourites (with Bayern Munich) to win the Champions League this season.