Ronaldo struggled with injury towards the end of last season, throughout the World Cup and in the early stages of the new campaign.
However, Ancelotti has said that the Portuguese's fitness does not need to be monitored ahead of tonight's La Liga clash with Elche.
"Cristiano has no need to rest right now. He's in top form and also in great physical shape and mental condition. We need him at the top of his game right now," Ancelotti told a press conference.
Ronaldo scored a hat trick in Saturday's 8-2 win over Deportivo La Coruna.