The Portuguese superstar has not quite hit the heights of previous seasons at the Bernabeu this time around and has seen his longevity called into question.
Ronaldo has hit a couple of braces in Madrid's last three outings, however, and with games against Real Sociedad and PSG up next, Zidane hopes to see his main man shine once again.
"He's extra motivated this season. He wants to show what he is capable of. I'm not concerned, I'm not worried," the Frenchman told reporters at his weekly presser.
"He is an outstanding footballer. There have been some times this season when he hasn't been able to get on the scoresheet but he is there when needed.
"On the big stage he performs. We've got a game on Saturday. That's the one I'm concerned about and then we will look ahead to Wednesday's game."
Ronaldo has a total of 17 goals in 23 La Liga and Champions League appearances for Real this season.