The club’s all-time record goalscorer was replaced at half-time during Sunday’s 2-2 Classico draw with Barcelona, after being injured while scoring his side’s first equaliser.
Real have not announced how long they expect the Portugal star to be sidelined for, but Zidane says Ronaldo - and fellow walking wounded Isco and Dani Carvajal - will be fine to face Jurgen Klopp’s Reds on 26 May.
Real will aim to win the Champions League for the third successive season and for the fourth time in five years when they take on Liverpool in Kiev.
Zidane is well aware how tough it will be against the free-scoring Premier League outfit, though.
He said in quotes reported on www.realmadrid.com: “It’s a great team. We know they have a little of everything: physical, technical, speed.
“It’s an English team who know how to fight. But there’s a while to go yet and I’m not going to go into details.
“(Mohamed) Salah is a great player and has had a great season, but he’s not mine.”