According to Ed Aarons of the Guardian, Palace value the player at a whopping £50 million, and there are a host of clubs tracking his progress with interest:
Zaha is said to be being considered as a possible alternative to Arsenal's Alexis Sanchez by Pep Guardiola, with the Manchester outfit hoping to snap him up at the end of the season for nothing when his contract expires.
The winger did have a spell at Manchester United earlier in his career, but he failed to live up to the potential he showcased at Palace. However, since returning to Selhurst Park, the Ivory Coast international has gone from strength to strength.
It's no coincidence that Palace have moved up the Premier League table rapidly since his comeback from injury.
As noted by Sky Sports Statto, he was exceptional in the Eagles' impressive 3-0 win over Leicester City:
The forward can shred opponents when at his best. Zaha has a rare blend of pace, power, flair and technique, meaning he can get at opponents in many different ways.
The Palace No. 11 has showcased plenty of versatility this season, too. While he can be effective on either flank, the Ivorian has been played as an orthodox centre-forward since manager Roy Hodgson arrived at the club.
There's also a newfound maturity about Zaha, as he's relished being the main man for the south London club.
Sports writer James McNicholas believes the player made the jump to United, in 2013, a little too early:
Now he's one of the most dangerous footballers in the division, and interest from the Premier League's elite is inevitable given he's plying his trade for a club languishing in the bottom half—even from City, who are cruising to the title after their incredible beginning to the campaign.
In Leroy Sane and Raheem Sterling, Guardiola does have some of the most potent wide players in the country, although Zaha would be a fine alternative to the devastating duo.
Of course, the issue for Zaha if he were to move to City would be getting regular minutes. The Etihad Stadium is home to some of the most creative footballers around, per Squawka Football:
At Arsenal, Chelsea or Tottenham Hotspur, there would potentially be more opportunities for Zaha, and that's something he'd surely consider if he were to move on, especially given how he toiled at Old Trafford.
Any decision may have to wait until the summer at least, though, and that's understandable from Palace's perspective. Regardless of any possible fee they would receive for Zaha, they are not out of the woods in terms of securing their top-flight status yet, and letting their key man go would be a huge gamble.