Crystal Palace chairman Steve Parish says any transfer involving the Eagles' star player Wilfried Zaha "has to be right for the club".
The Ivory Coast forward, linked with Everton and Arsenal in 2019, has expressed a desire to challenge himself at the top level of European football.
Zaha has played almost 400 games for the club after joining as a youngster.
"We understand his position," Parish told BBC Sport. "It's no secret that he would like to challenge himself."
Parish added: "But it has to be right for the football club. He understands that as well.