Allegri wants the 33-year-old involved against Roma, as Juve look to prolong their unbeaten start to their league title defence, but he is happy for Ronaldo to miss either the trip to Atalanta on Boxing Day or the clash with Sampdoria on December 29.
"Ronaldo plays tomorrow, and he'll then miss one of the next two games," Allegri told a news conference on Friday.
Saturday's game at the Allianz Stadium sees Juve face a Roma side who had gone five consecutive games without a win in all competitions before last Sunday's 3-2 victory over Genoa.
Pressure has been mounting on head coach Eusebio Di Francesco, but Allegri insists his opposite number will win back his detractors.
"They're a very good team. Among other things, they're the only Italian team along with Juventus still left in the Champions League," he said.
"Di Francesco has shown he has all the qualities to do well, and I'm sure he'll prove it this year. Last year, he took the team to the Champions League semi-final while fighting Napoli for second place."
Allegri plans to rotate his side over the next two weeks, but it is likely he will be without winger Juan Cuadrado, who could need surgery.
"Cuadrado is in Germany to assess whether or not he needs an operation," he added. "In midfield, we have five options who will rotate over the next few games."