At 32, Benzema has less than two years to run on his current deal and in the best form of his career.
He told Universo Valdano: "I don't know until when I will play at a great level.
"I go there season after season. I have a contract until 2022, we'll see…
"After that, I always leave the door to my house open to Florentino (Perez, Real Madrid president)."