Winger Zaha joins Manchester United in a £15million switch after the Championship play-off final showdown with Watford, and Eagles manager Ian Holloway is backing him to sign off in style.
"It would be a nice fairy story," Holloway said.
"Wilf will help Manchester United win games. I've never heard anyone talk about one player so much.
"He just needs to be left alone to play because his talent is so fresh and real and exciting.
"He might do enough right to get us what we need and that would be wonderful. We feel like we are losing a family member."
Palace only agreed to sell Zaha to Old Trafford, where he will be Sir Alex Ferguson's final signing for United, if they could loan him back for the rest of the season.
The 20-year-old responded to the challenge of helping the Eagles join him in the Barclays Premier League next season with both goals in their 2-0 semi-final win over Brighton.
And Holloway feels Zaha is ready to repay Palace's faith in him once more as they battle for the estimated £120million jackpot on offer for the Wembley winners.
"How would he have been feeling if we'd been selfish and denied him that opportunity? What would he have produced for us after that?" added Holloway.
"I think he will pay us back. We need him to play well because he's a huge part of what we do."
Zaha, who has been at Palace since he was eight, came to United's attention when he was named the Championship's player of the year last season.
He has continued to impress this term, scoring eight goals and making his England debut as a substitute against Sweden in November.
"Wilf has got all the plaudits and rightly so, he's had a great season and he had a great game against Brighton," said Palace skipper Mile Jedinak.
"But he knows, as we all do, that we can only achieve what we want to achieve as a team and we're all pushing towards the same goal."
If Palace do secure promotion at least defender Damien Delaney will only have to face Zaha twice, rather than every day in training.
"Sometimes when you're playing against him he drives you a bit mental, he can make you look a little bit foolish," said Delaney.
"But I don't think he knows any other way. He's one of those naturally gifted players - you give him the ball and tell him, 'go and enjoy yourself'.
"Obviously you have to give him a bit of structure in the team shape, but in general he's a one-off, such a good player."