Sergio Ramos has a contract that expires this summer.
The Real Madrid captain is 34 and will be pursued by the biggest clubs in Europe should Real fail to tie him down to a new contract.
Former Man United striker Dimitar Berbatov has urged the Red Devils to sign Ramos.
Berbatov told AS: “Ramos would not only bring experience to Manchester United, but also many goals.
“With the Red Devils he could do very well despite being 34 years old. He is a top central defender, among the best players in the world, and it doesn’t surprise me that there are many teams interested in buying him now that he can freely agree with anyone.
“I guess Real is skeptical about renewing in view of his age.”
However, former RM GM Valdano is confident Ramos will stay –
Valdano told El Transistor: “He will end up renewing with Real Madrid.
“It would be a mistake on both sides if it were not. The same thing happened with Cristiano (Ronaldo).
“Real Madrid was left without the Champions League and Cristiano without the Ballon d’Or.”