Coventry chairman Ray Ranson has warned potential Premier League suitors that star asset Keiren Westwood will not be leaving the club for free.
The Republic of Ireland goalkeeper, who has one year to run on his contract at the Ricoh Arena, is being linked with a host of clubs, including Sunderland.
While the Sky Blues are still trying to tie the 25-year-old down to a new deal, Ranson has also insisted they will not let their prized asset move on for free.
While no official offers have yet been received for the keeper now the summer window has reopened, Ranson is expecting contact.
He said: "All it is at the moment is speculation, we are desperately trying to get him to sign a new contract as he's got 12 months left.
"Until he or his agent turn around to us and say he's definitely not signing a new contract then we are very optimistic.
"But there is interest in him and rightly so, he's an international goalkeeper now and he's the best goalkeeper outside the Premier League - and he's only getting better.
"So it's no surprise all the big clubs want him. We're not soliciting any firm bids but we are expecting it now the window's opened."
Asked what would happen if the situation were to remain unchanged until next summer, Ranson added: "If it gets that far then we would lose him for nothing on a Bosman free transfer - so that won't happen, I can assure you.
"We'd be forced to sell him. He won't be leaving this club for nothing, that's for certain."