Lille chairman Michel Seydoux claims failure to qualify for the UEFA Champions League group stage would not force the club to part with Mathieu Debuchy.
The France international is known to be a top target for Premier League side Newcastle, while Primera Liga giants Real Madrid have also been linked with a late approach.
Any side hoping to wrap up a deal will have to move quickly, with the summer transfer window set to slam shut on Friday.
Lille hope the deadline will pass with Debuchy still on their books, but appreciate that there are a number of factors to take into consideration.
A 1-0 defeat by Copenhagen in the first leg of their Champions League play-off has left the French side with it all to do if they are to reach the group stage.
Were they to drop out of Europe's premier club competition on Wednesday, interest in Debuchy is likely to intensify.
Seydoux, though, maintains that he will not be forced into a sale and remains optimistic regarding Lille's chances of turning the Copenhagen tie around.
He told L'Equipe: "If we fail to qualify for the Champions League would I be forced to accept Newcastle's proposal? You know that I am not very flexible when it comes to business.
"We didn't show enough fighting spirit during the first leg in Denmark but I feel we found that last Saturday against Nice (in a 2-2 draw)."