Lopez believes elimination from the Champions League could force Real's hand and see Ronaldo sold.
He told Telefoot: "Today's Cristiano, at 33, is not the Cristiano I knew at age 17-18. It is the transformation of a genius and a person who can understand how he can always be better.
"But there is the question of whether to continue with Real or leave. I understand the negotiations that are going on right now. If Real Madrid gets eliminated by PSG, everything will be questioned. They will have to redo everything.
"I am sure that if he leaves Real, he will go to a big club."