The France international has been battling Gonzalo Higuain for the lone-striker role in the Real Madrid team, but the report claims he could move on this summer to secure regular first-team football.
Arsenal have been linked with a summer move for the Frenchman, but Ramos, who is reportedly charged with marking the striker in training, is desperate for him to stay at the Bernabeu.
Speaking while on international duty with Spain, Ramos said: "To question a player like Benzema is madness, for both Real Madrid and France.
"He is a very special player who can make a difference. He is a very good striker who's good at Real and his national team.
"When he is right there are few players who can reach his level.
"I thoroughly know that you have to constantly mark him and if you forgot for a moment he will lose you and score."
The defending La Liga champions currently sit second in the table, 13 points behind league leaders Barcelona. Benzema is the club's third top scorer this term, but he's bagged just eight league goals.
10 of his 22 appearances have come from the bench though, but Higuain has managed 11 strikes and the club's top scorer Cristiano Ronaldo has 27.