It was recently rumoured that Ronaldo is seeking fresh terms to once more become the highest paid player in the world after being overtaken by both Lionel Messi and Neymar this year.
That had followed speculation that the five-time Ballon d'Or winner was seeking an exit from the Bernabeu after becoming unhappy, with the possibility that the two pieces of gossip are linked.
Ronaldo's current Real contract runs until 2021, expiring a few months after his 36th birthday, but a new one isn't a priority for the club just yet.
"I'm not going to go into everything before the game [against Barcelona], that is not the issue. What Cristiano has to think about is the match. It's the same for everyone," Zidane is quoted as saying by Marca ahead of El Clásico.
"What I think is that Cristiano, what he has done and what he is doing, deserves all of the club's respect, but only after the winter break will we talk about it."
Ahead of the clash with Barça, Real trail their rivals by 11 points. A win at the Bernabeu would cut the deficit to eight points, while victory in their game in hand further down the line would also eat into the Catalans' lead.
Three points the other way on Saturday, however, would extend the gap to 14 and possibly knock the reigning champions out of the title race before Christmas.