The Whites saw a bid of £250k for the left-back turned down last month and Fox is now in talks with Colchester United who have had an offer, around £350k, accepted by Walsall.
Wise said: "We put an offer in and they didn't accept it. They've accepted an offer from Colchester but we wouldn't be prepared to go to that. He's out of contract at the end of the season so we'll stay tight and get on with what we have to do. There's possibility we'll still get hold of the player but we'll have to wait and see."