Leeds chairman Professor John McKenzie insists the club "cannot allow" Harry Kewell to see out his contract and walk away from Elland Road for a cut-price fee.
The Australian striker is in contract talks with Leeds but has been linked with Manchester United and Liverpool recently.
But McKenzie is desperate to secure Kewell's signature on a new deal and avoid a situation similar to the one that saw Lee Bowyer stall on a contract only to leave for West Ham for £100,000 sterling in January.
McKenzie told the Yorkshire Post: "I have already spoken to Harry's agent a few times and we are still very confident of putting a deal together. We hope that Harry will stay.
"I will be looking to meet his agent again next week when I believe we will be in a position to put a new proposal to him.