Ronaldo sustained the injury during the Club World Cup final victory over Gremio and had trained alone as a "precaution", with the club insisting the 2017 Ballon d'Or winner would be fit for Barca's visit.
He was then pictured training alongside the rest of his team-mates as normal on Friday and coach Zinedine Zidane confirmed in his pre-match news conference that Ronaldo is fine and will feature.
Zidane said: "He is fine, he's 100 per cent. He has trained today and that's what interests me. I'm not going to get sidetracked into other things.
"The only important thing is the game and that’s all Cristiano has to think about on Saturday. What Cristiano has done and doing at this club, he deserves all the respect he gets."
El Clásico is coming... pic.twitter.com/MqSe7c1o2r— Real Madrid C.F.🇬🇧 (@realmadriden) December 20, 2017
Gareth Bale is another Madrid star who has suffered with injuries of late, but the Wales international featured in the Club World Cup and, although Zidane would not be drawn on whether he can start against Barca, the Frenchman is willing to accept his players' conclusions as to their own fitness.
"I always believe in my players, believe in communicating with my players," Zidane added. "I trust my players.
"It happened last year [Bale getting injured in El Clasico], but it can happen with any player, getting injured.
"The important thing for me is when I ask the players if they're 100 per cent, I believe them, but things can happen.
"You'll see tomorrow if he plays. As always, I can't tell you. That's for me to think about.
"The good thing is everyone is fit.
"That's a good thing but also bad, because I must leave players out."