Mesut Ozil admits keeping Cristiano Ronaldo is crucial for Real Madrid's future.
Ronaldo continues to be linked with former club Manchester United this summer.
Ozil told CNN: "Cristiano Ronaldo is very important to the team, just look at the goals he has scored in the past few seasons.
"He's a great person off the field. I hope he can stay here for a long time because he can help us win important titles."