Chelsea are reportedly planning to test AS Monaco's resolve with a big-money January bid for midfielder Tiemoue Bakayoko.
The 22-year-old has already ruled out leaving the club in January, but admitted that he is keen on a move to the Premier League in the future.
Monaco are also unwilling to sell the France Under-21 international as they look to push for the Ligue 1 title in the second half of the season.
However, Le Parisien reports that Chelsea have not been put off by that and are lining up a bid that could entice the French outfit to sell this month.
The Blues, who currently lead the way at the top of the Premier League table, have money to spend in the transfer window following the sale of Oscar to Chinese Super League side Shanghai SIPG.