Newcastle are desperate to keep the striker, who has netted 15 times for the club this season.
When asked about a £10million release clause, Redknapp said: “I think you will find it is a lot less than that.”
When asked if it was as little as £7million, Redknapp added: “Even less than that.”
Liverpool, Sunderland, Everton, QPR and Tottenham are among the clubs being linked with the striker.
