Everton have rejected an approach from Paris St Germain for defensive midfielder Idrissa Gana Gueye.
The reigning French champions lodged a bid in the region of £22m, but it was rebuffed by the Toffees.
Everton have stated the player is not for sale, though four days still remain in the January transfer window for clubs to conduct business.
PSG, who face Manchester United in the last 16 stage of the Champions League, are expected to return with a revised offer.
It is understood Gueye is keen to make the move to the Ligue 1 champions, though has not acted to force a transfer.
The player signed at Goodison Park two-and-a-half years ago, arriving in a £7.6m move from Aston Villa.
Gueye featured heavily for his nation Senegal in last summer's Russia World Cup, and has turned out 20 times this season in the Premier League.
Everton currently sit 11th in the Premier League table, having taken 30 points from 23 games played.