Zidane is recognised as one of the greatest players to grace a football pitch, having won the World Cup with France and plenty of trophies with his various clubs - including the Champions League with Real.
However, the former France international was more of a creator of goals and does not have the phenomenal goal-scoring statistics of Ronaldo.
Quizzed about how Ronaldo compared with players he played with during his career, the Los Blancos mentor said he wished he could celebrate more goals like his talisman and former teammate, Ronaldo from Brazil.
Zidane said: "As a coach, he is the best player I have had.
"I wasn't able to play with him, unfortunately - but I did play against him. His statistics are amazing.
"I played with the Brazilian Ronaldo, who was also an extraordinary player who scored a lot of goals. I'm jealous of them because I didn't have those numbers.
"I got a lot of assists but I just passed the ball and didn't have their goalscoring ability, so I never had the same feeling - that thrill of the ball hitting the net - as them. They are decisive players."