"He made a mistake and knows it," Ancelotti said after the World Player of the Year was banned after being sent-off for lashing out at Cordoba defender Edimar during Real Madrid's 2-1 win last weekend.
Ronaldo apologised after the match but will miss home games against Real Sociedad and Sevilla, but will be free to feature against La Liga champions Atletico Madrid on February 7.
Madrid currently lead Barcelona by a point at the top of La Liga, but also have a game in hand.
"Now he's going to serve his penalty and I hope it won't happen again. He's going to use this time to work well and be in top form to return for the derby."
Ancelotti dismissed reports that Ronaldo was suffering left knee problems.
"The problem he had with the tendon last year has been totally resolved, he has no problem, none at all," said the Italian.
"He always seems at top level to me. It's possible that some think that he isn't because of physical problems, but he has none.