Ronaldo was dismissed in the second half of the encounter after an altercation with Carlos Gurpegui and Ander Iturraspe, and could receive a ban of more than three games should the Spanish FA (RFEF) deem the offense to be an act of violent conduct when the disciplinary board meets on Wednesday.
Ancelotti, however, believes the Portugal international will escape with a one-match suspension and will be available for the first leg of the Copa del Rey semifinal with Atletico Madrid on Wednesday evening.
"I don't think we will have to wait for the committee's decision. I am convinced that he will not be heavily punished for what happened. Cristiano will start on Wednesday," the Italian coach said at a press conference.
"I don't know what to say about Ronaldo's gesture when he left the pitch. I don't think he meant anything bad with it. He was obviously unhappy with his dismissal as it was a harsh decision. Cristiano is often provoked on the pitch and concedes a lot of fouls. His gesture wasn't that bad."
Ancelotti also revealed Gareth Bale and Raphael Varane could both make a return to the side following injury layoffs, and admits he is eager to keep a clean sheet in the first-leg clash at Santiago Bernabeu.
"Every derby or Clasico is the most important game for the club and the fans," he continued. "Tomorrow a different Real Madrid will play compared to the team that played Atletico in the League. Atletico are organized, solid and compact. Simeone is doing a great job and has a great team. He says they are not favorites to win the title to get rid of pressure.
"Atletico have maintained the same quality and are still organized. They are more confident now because they've won many games. We will have the support of our fans tomorrow which is always important. We have to try to keep a clean sheet and win the game."