Everton have seen an £18 million bid for Yannick Bolasie rejected by Crystal Palace.
Ronald Koeman set his sights on the attacker as the Blues look to bolster their attacking options heading into the new Premier League campaign.
Ahead of Saturday’s opening visit of Tottenham, only Idrissa Gueye and Maarten Stekelenburg have joined, from Aston Villa and Fulham respectively.
Palace are prepared to part with Bolasie following the signing of Andros Townsend but have rebuffed Everton’s initial approach.
A renewed bid of £20 million is expected but the Guardian claim that the Eagles are holding out for a deal closer to £30 million for the Congolese forward.
Keith Millen, the club’s assistant manager, refused to comment on the 27-year-old’s future following Monday’s friendly win over Farnborough.
He said: “I don’t comment on reports or stories. The fact is Yannick is with us and he is a big part of what we’re about.
“He has worked hard in training, and speculation with players isn’t great this time of year, it’s unsettling but we have to try and deal with it. Until a deal is done, he’s in the squad and ready for the West Brom game.
“We do not want to lose any players. We want to strengthen in the attacking areas, we need more goals in the squad and we are working hard to try and get more goals brought into the club.
“Yannick is a key part of that, whether he plays wide or as a 10 and we want to keep all our best players.”