Real need victory to keep pressure on LaLiga leaders Atletico Madrid.
Zidane said, "I'm very proud of my squad. After everything we've been through, we've just kept on working and been focused on the fact that we could win things come the end of the season. My players have given their all, they're giving their all and when you're a coach, that's as good as it gets.
“I'm proud of them every season because they always battle and compete. They enjoy playing and training and that has certainly been the case this year because we've had so many difficulties, what with the injuries and some strange things. I'm delighted with what they're doing. The players always want to compete. This is a side that has kept on working and has tried to do things properly and that's why I'm perhaps prouder this year than every before. I'm delighted with how they're doing."
On Athletic Club, Zidane also said: "We'll be looking to make a strong start and compete throughout the 90 minutes, just like we did the other night. We have to worry about the things we can control, which is our game tomorrow. We can't control anything else. We want to get the three points. We're up against a very good side who are performing really well as a team and we'll be giving our all."