The Ivory Coast international has been attracting interest from across Europe this summer following a standout campaign with the Eagles, where he scored nine goals and claimed five assists in the Premier League.
Zaha is supposedly being touted by a number of clubs in England, namely Everton, but the 25-year-old is also on the radar of German club Borussia Dortmund following the departure of winger Andriy Yarmolenko, who has joined West Ham.
However, Sunday Times writer Castles believes that Chelsea would be in pole position for Zaha's signature as the Crystal Palace star is eager to stay in London next season.
Castles told the Transfer Window podcast via the Sport Review: "It raises the possibility of a move to Chelsea. Chelsea are preparing for the chance that Willian and Hazard move this summer. Zaha is a potential option. He is cheaper and younger than those two. He would prefer to stay in London."
It has been suggested that the Blues' failure to qualify for the Champions League will weaken their chances of retaining the two forwards, both of who featured heavily for their respective countries at the World Cup this summer.
Hazard was named in the starting lineup for the Red Devils in their third-place playoff match against England on Saturday, while Willian was knocked out by his Chelsea teammate in the Seleção's quarter final defeat to Belgium.