Ronaldo has again declared this week he won't consider renewing his existing deal.
Di Maria said: "That's personal. Each individual knows what he has to do. He still has a contract. From my point of view he is a very important player for Real Madrid and the club need him. I think he has done things in the best way to get the renewal. Then it's his decision if he wants to stay, if he wants to renew or not.
"When Cristiano plays there is an obvious difference, he is a very important player and it always shows when he is not playing. He can play a definitive role at any moment, but we have other players who are doing very well and are in good form too."