The Brazil international has impressed in recent weeks after the Hoops were 1-0 winners at Chelsea before picking up credible draws against Tottenham and West Ham.
Madrid could be without Iker Casillas for up to three months after the Spain captain broke a bone in his hand during Los Blancos’ Copa del Rey quarter-final victory over Valencia on Wednesday.
José Mourinho is looking to draft in a temporary replacement for the Madrid shot stopper, and the Portuguese coach worked with César during a successful two-year spell at Internazionale.
But Redknapp insisted the Hoops would not be letting the Brazilian, or his second-choice goalkeeper Robert Green, leave this month.
“I don’t want to sell César or Green. They’re two good quality keepers. They’re our backbone. We need to keep them here,” said Redknapp.
“Cesar is a top keeper and you can understand why people would want him, but we’ve not had any enquiries.”
Redknapp also revealed that he is interested in signing South Korea defender Yun Suk Young, with Anton Ferdinand linked with a loan move away from the west London side.
But the 65-year-old was adamant no players will be sold until he strengthens his QPR squad.
“I can’t let anybody go unless we get some players in. We need to strengthen, not weaken the side and we have been trying,” he added.
“I haven’t been home for 12 days. (My wife) Sandra said she’d forgotten what I look like. I said I look like Paul Newman. In my dreams!”
Get 8/1 enhanced odds on Tottenham to win or 11/1 enhanced odds on Liverpool to win at White Hart Lane on Saturday afternoon. Click here to sign up now. T&Cs apply.
MORE: Latest Man Utd news
MORE: Latest Arsenal news
MORE: The latest football news