The Bees are all-but resigned to losing the prolific winger - who trained with his team-mates this morning - this summer having already sanctioned the sale of last season's top scorer Ollie Watkins to Aston Villa for an initial £28million.
Palace are keen to invest in attacking talent during this window while they are also looking to bring the average age of their squad down. The Eagles have already signed Nathan Ferguson, Eberechi Eze and Michy Batshuayi - the latter on a season-long loan from Chelsea - and are keen to add one more.
The club are also keeping a close eye on Sassuolo's Jeremie Boga - formerly of Chelsea - should Wilfried Zaha move on this summer. The winger would set Palace back around £35million should they make a move, though there has been little to no interest in Zaha so far this summer.