The centre-back has been suspended and fined £25,000 by the FA after he sent a tweet on September 1 that "included a reference to gender".
A fellow Twitter user sent the message "Maybe QPR will sign a good CB they need one", and Ferdinand replied by saying "get ya mum in, plays the field well son! #sket".
In response to the punishment, Redknapp told reporters: "We've not seen the written evidence from the FA on the Ferdinand charge so I can't comment on it. I don't know too much about it and can't comment on it. We'll talk about it once we've seen the written evidence."
Ferdinand has also been ordered to attend an "education programme" arranged by the FA within the next four months.