The former Inter Milan keeper missed QPR's defeat to Arsenal last weekend due to a back problem, with Robert Green stepping in for the Brazilian.
And Redknapp admits it is unlikely Cesar will be playing for the recently-relegated side next season.
"He's had a little bit of back injury," said the Hoops boss.
"But it is a difficult one because I don't see him playing here next season, so I want to play Rob Green.
"I think Julio is a player for a top club, a top Italian team, a top Spanish team or a top Premier League team. He is good enough to play anywhere.
"Rob has come in and done well. Rob will probably be my goalkeeper next season.
"Julio is in the Brazil team. He is not a player for the Championship.
"He has got a World Cup coming up. He needs to be playing in the Premier League or a big league abroad."
However, the QPR boss is hopeful defender Chris Samba will stay at Loftus Road next season.
Samba, the club's record signing from Anzhi Makhachkala for a reported fee of £12.5million in January, also missed last Saturday's 1-0 defeat to Arsenal due to injury.
But Redknapp's plans to take relegated QPR back to the top flight include the former Blackburn defender.
"I'd like to keep him, he'd be the best centre-half in the Championship," Redknapp said.
"He had one bad day at Fulham and everyone got on his case. He's a good player and we need him back playing.
"(But) I don't know what will happen."