Lille director general Frederic Paquet claims Moussa Sow is not for sale, with the club having already blanked one offer from Fenerbahce.
The reigning Ligue 1 champions are reluctant to part with one of their most potent attacking weapons, even if his contract is running down.
Sow has a little under 18 months remaining on his current deal and Lille are desperately trying to tie him down on fresh terms.
They are aware that the 25-year-old has attracted interest from the Premier League in the past, and that he has expressed an interest in trying his luck in England.
They hope Sow can be persuaded against making such a move, with it their desire to see him pen a contract extension.
It is, however, not a team from England who is causing them transfer concern at present, with Fenerbahce having expressed an interest in taking the Senegal international to Turkey.
"There has never been negotiation between Fenerbahce and LOSC," Paquet told La Voix du Nord.
"We received an offer from Fenerbahce, but we haven't responded.
"No squad member will leave in January. I want to make it very clear - Moussa is not for sale and there is no negotiation with Fenerbahce."