Wednesday, managed by former Iron boss Brian Laws, have put in a bid for Sharp which could rise to £1.5million if the reach the Premiership with Sharp as a player.
United turned down two offers of more than £2m in the January transfer window so it would be a surprise if this was accepted, but Adkins admits the club will be effectively powerless to stop Sharp leaving if he wants.
"I think this bid will not be accepted but we have to sit down with Billy and see what he wants to do," he told BBC Radio Humberside.