The 35-year-old joined the club in the summer on a free transfer from Manchester United, but has struggled to find his feet at Loftus Road, becoming part of a defence that has conceded 18 goals in eight matches.
However, Redknapp is adamant that his side's problems are not all down to their defenders, and feels that Ferdinand has been used as a scapegoat.
He told reporters: "It has not been as easy for him obviously but it's funny how everybody is looking for a scapegoat and it's all Rio's fault.
"Obviously it's been different for him but when we didn't play well it wasn't because of Rio. When we went to Tottenham and got beat by four I thought Rio and [Steven] Caulker were our two best players, the only two who came out with any real credit.
"Last week, when he wasn't in the team he was part of the team even though he didn't start, and that's important - you need people like that round the football club."
QPR face Aston Villa in their Premier League clash later today.