"If he turns on his mobile I might be able to get hold of him," said the Leeds boss.
"There is no ultimatum, but it would be sensible to get the situation sorted out. I would like to know sooner rather than later.
"Harry has a year to run on his contract and has been offered an extension. He's a very good player and I would love him to sign a new deal.
"But we can't afford to lose out financially the way we did with Lee Bowyer.
"If he leaves it does give me licence to bring in players. I have identified where I need strengthening and I have made inquiries."