Chelsea are reportedly set to return with a new £30million plus offer for the Croatian, but Redknapp insists the club's stance that the 25-year-old will not be sold has not changed.
"I don't know where it's at and Daniel (Levy) has said all along that he is not going to sell Luka so that is probably it as far as I know," Redknapp said.
"There is no sign of him going. If he doesn't go it's an area we need to strengthen and we have one or two irons in the fire.
"We are trying (to get players in). We have some names and we are trying to get one or two in. We need to do a little bit of business."