The Daily Star Sunday says Redknapp wants two more years added to his current deal, which runs out next year.
But Tottenham chairman Daniel Levy has made no move yet.
Redknapp is concerned nothing has been put on paper and argues that the club wouldn't allow Gareth Bale's contract to run down - so why delay his deal.
Chelsea are monitoring the situation.
Redknapp has little more than a year to run on his current deal, leading to speculation that Levy is looking to the future.