The new Hammers boss has indicated that the Potters must improve their initial offer of around £3million if they are to be successful in their pursuit of the striker.
"I believe at this stage that the offer is not good enough. It is not to the club's valuation," he told The Sentinel.
"We are keen to keep our key players. However, we have lost our Premier League status and our financial position has to be addressed.
"A part of that might be players are sold back to the Premier League, but only so long as that is right for our club."