The 26-year-old has been on international duty with Ivory Coast at the 2019 Africa Cup of Nations and would like to leave the club after his post-tournament break, according to Sky Sports:
Crystal Palace have already rejected a bid of £40 million from the Gunners for Zaha and want "double that fee," according to Rich Jones at the Mirror.
Zaha's preference is to move to Arsenal, as he wants to prove himself on the big stage, according to Sky Sports reporter Kaveh Solhekol:
The winger spent two years at Manchester United but failed to make an impact at Old Trafford.
He made just two Premier League appearances in two years and said he was not "given a fair opportunity" in an interview with Adrian Kajumba for the Daily Mail.
Emery has said that he expects the club to bring in "three or four players" before the close of the transfer window, per BBC Sport.
He added: "We are being very, very demanding and we are first speaking about the possibility to sign very big, very expensive players."
Yet the Gunners are working with a limited budget and have only £40 million to spend, meaning "they need to agree to pay deals in instalments," according to Simon Collings at the Evening Standard.
Arsenal vice-chairman Josh Kroenke has spoken about the club's budget, per Sonny Cohen at the Guardian.
"It's no secret that we have a Champions League wage bill on a Europa League budget right now," he said. "That’s a fact. And one that we're figuring out how to face internally at the moment."
Their financial restrictions make doing a deal difficult. Zaha is Crystal Palace's star player and racked up 10 Premier League goals for the club last season to notch a landmark:
The winger also shone when Crystal Palace beat Arsenal 3-2 in April:
Crystal Palace will not allow him to leave on the cheap and have already proved they can drive a hard bargain in the transfer window.
The Eagles sold full-back Aaron Wan-Bissaka to Manchester United in June for £50 million, per David Ornstein at BBC Sport.
Zaha is widely regarded as being one of the best wingers in the Premier League, and Crystal Palace look to have a real fight on their hands to keep him at the club this summer.
The Ivory Coast international could be a real asset at Arsenal if he were to move and link up with strikers Alexandre Lacazette and Pierre-Emerick Aubameyang, but the club's financial restrictions will complicate any potential deal.