The club this week relaunched their charity as the Palace for Life Foundation, and both chairman and manager believe its influence on the local community is helped by those players' presence.
Zaha has been attracting fresh interest from Tottenham and the Ivory Coast worldwide is hitting the heights with his individual displays.
Since then he has matured, and this season his contribution to Crystal Palace has been huge, especially in recent times under Sam Allerdyce, with the club managing some excellent results that are seeing them fight a solid relegation battle.
A return to Manchester therefore seems unlikely with such bad memories of his time in the north, whereas joining Tottenham would enable him to remain in London - and ultimately play more first-team football under a manager who has pursued his signature for some time now.
"Wilf, us and the clubs that want him will decide his future in the end", Allardyce said.
With four points from his first eight games, Allardyce initially struggled to turn things around, but has now put his own stamp on Palace, having picked up five wins from last six games and kept four clean sheets in the process.
And discussing the rule, Parish said at the launch of the revamped Palace for Life Foundation: "At the moment you can't stop anyone from anywhere in the European Union coming and joining an academy, and Federation Internationale de Football Association rules are that you can't sign anyone from another country unless they are 18". "Our attacking players are enjoying themselves more than they ever have this season and are flourishing in possession and scoring goals, so we have everything right at the moment and we just have to keep it up for a little bit longer".
"There's a picture painted of the modern Premier League player, that as a generalisation just isn't true", said Parish. Now you have got competition. It is called China.
Croydon-born Jason Puncheon and Wilfried Zaha starred in Palace's 3-0 win over Arsenal on Monday, and the pair have been heavily involved in the foundation's programmes. The Premier League has got bigger competition than ever before. That is a financial decision to secure the rest of your life. "So who knows what the market forces will bring in terms of the price?"