Zidane enjoyed a star-studded playing career, winning the World Cup and Champions League, but wishes he had enjoyed the thrill of scoring goals as much as his star attacker and namesake Ronaldo Nazario, his former Santiago Bernabeu team-mate.
The Real boss was asked how Ronaldo compared with the players he played with during his career and conceded he was envious at their goal tallies.
"As a coach, he is the best player I have had," Zidane said of the Portugal international.
"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."
Zidane also spoke of his respect for opposite number Diego Simeone ahead of the first leg of the last-four tie at Santiago Bernabeu on Tuesday.
"Simeone and Mono [German] Burgos are doing a great job for their club," said Zidane. "I know Burgos a bit - I like him and have great respect for him.
"I only know Simeone from playing against him but they are two people I have enormous respect for both of them for the job they are doing. Simeone is a very experienced coach."