The two teams play one another in the Premier League clash at the London Stadium on Tuesday. However, they are also reportedly at loggerheads for Lille captain Amadou's signature.
Crystal Palace have allegedly been told to pay £17.6m after their two bids of a 'loan with the option to buy' and £16m were rejected by the Ligue 1 club.
However, West Ham have also enquired about the player as David Moyes looks to replenish a squad that has been hit with 14 separate casaulties.
Lille are under pressure to sell players due to Financial Fair Play restrictions and must raise at least €25m to avoid a potential relegation to Ligue 2, so a transfer looks likely for 24-year-old if the price is right.
Amadou would be a good addition for either side as he can play as a holding midfielder or a centre-back, making 21 appearances already this season.