Ronaldo left Madrid ahead of the 2018-19 season, joining Juventus in a blockbuster €112million deal after three consecutive Champions League titles under Zidane.
The five-time Ballon d'Or winner enjoyed great success during his time with Zidane at the Santiago Bernabeu, also winning LaLiga in 2016-17.
Ronaldo heaped praise on Zidane – who is in his second stint in charge of Madrid – as he discussed the pair's relationship.
"The confidence that a player needs doesn't only come from himself but also from the players around him and the coach," Ronaldo told DAZN.
Every athlete has moments that define their career. #DAZN gives fans an in-depth look of the games that defined the careers of @neymarjr @Cristiano and José Mourinho in the new #DAZNOriginals, The Making Of. pic.twitter.com/JCLcDig6mA— DAZN (@daznglobal) August 1, 2019
"You need to feel like you are an important part of the group and Zidane made me feel special.
"He helped me a lot. I already had a lot of respect for him but working with him made me admire him more.
"That's because of what he's like as a person, how he talks, how he led the team and how he treated me.
"He'd tell me, 'Cris, relax and just play your game - you are the one who is going to make the difference.'
"He was always honest with me and that's why I'll always have a real affection for him."
Ronaldo scored 21 Serie A goals in his first season with Italian champions Juventus, who won their eighth successive Scudetto.