Palace boss Patrick Vieira has zeroed in on Lens man Doucoure as a potential addition during the window, but the Premier League club are determined not to pay over the odds.
Lens are prepared to let the Mali international depart, but are sticking to an asking price of £26m.
As a result, Crystal Palace may need to move on to another target as they are unwilling to pay such a sum for the player.
Doucoure, 22, is a product of the Lens youth system and helped the club return to Ligue 1 in 2020.
The defensively minded midfielder clocked 34 appearances in Ligue 1 for Lens in the recently concluded campaign, only missing four matches due to suspension.
He was sent off in a 2-0 win at Monaco and subsequently banned for two games, while he missed meetings with Nantes and Lille due to an accumulation of yellow cards.
Doucoure has been capped eight times by Mali and it remains to be seen if Lens will soften their stance as the transfer window progresses.
