Fulham manager Martin Jol hopes to keep Andrew Johnson at Fulham and has warned any potential suitors that they will have to dig deep in order to land the striker.
The former England international's contract is running down and he will become a free agent in the summer if fresh terms are not agreed.
The Cottagers are refusing to give up on their efforts to agree an extension, but they are aware that interest is mounting in Johnson's services.
Capital rivals Queens Park Rangers have already seen one bid knocked back, while an approach from Blackburn was blocked last week.
Rovers remain in the hunt, though, with added firepower required if they are to pull away from trouble.
Fulham boss Jol accepts that the speculation regarding Johnson's future will continue for as long as he allows his current deal to tick down, with rival clubs desperate to bolster their own ranks.
He would prefer not to part with the 30-year-old during the winter window, but accepts that a sizeable offer could force his hand.
Jol said: "If you get a big offer, you should get a very good player and I think Andy Johnson is a very good player. Anything else is almost impossible.
"Andy is an important player for me. It's important to keep your players - particularly if you can't get other ones in. We'll have to wait and see."