Samba, the club's record signing after joining from Anzhi Makhachkala for a reported fee of £12.5million in January, missed last Saturday's 1-0 Barclays Premier League defeat to Arsenal due to a knee injury.
Redknapp's plans for the npower Championship include the former Blackburn defender as he bids to take relegated Rangers back to the top flight at the first attempt.
"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."
Cesar, who was disciplined for being pictured in a Chelsea shirt while dressed as David Luiz at his Brazil team-mate's birthday party, appears likely to exit Loftus Road.
Redknapp insisted the former Inter Milan goalkeeper missed the Gunners defeat due to a back problem but that Robert Green would be preferred in the remaining games of the Premier League as Cesar is near-certain to move on this summer, with the England international first-choice next term.
"He's had a little bit of back injury," Redknapp said. "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."