AC Milan coach Carlo Ancelotti insists Ronaldo can play a key part in their campaign for the second-half of the season.
Ancelotti added: "It has been an amazing year - everyone knows that. We will do what we can to make 2008 a year to remember like 2007.
"But first, we have to think about preparing for the derby. I think that it has been so much simpler to adapt to the change in time zone coming back, so the players should be in excellent condition.
"I don't think that it will be an easy game as they are such a strong side, especially going forwards.
"However, I think that the victory in Tokyo could be the springboard that brings us back into the title race and helps us reduce the distance between Inter and ourselves."