The Brazilian has been strongly linked with a return to former club AC Milan.
Mourinho told Marca: “I don’t know what will happen with his future and neither does he, but between us there are no doubts because he knows what I think and the market is open until August 31.
“Anything can happen. He could be a Real Madrid player next season and if he stays I would be delighted because we have a great relationship and he offers us things.”