The 19-year-old broke into the Rovers first team just over 12 months ago, and has been a regular this season under Jon Dahl Tomasson.
Wharton has made 29 appearances for Blackburn during the current campaign, and scored in his most recent outing against Huddersfield Town in the Championship.
However, that looks set to be his final appearance for the club, with a move looking imminent after being an unused substitute against Wrexham in the FA Cup on Monday night.
BBC Sports claim that Wharton will travel to London today in order to finalise personal terms over a deal which could be in the region of £18.5m, rising to £22m.
Impressing in the Championship has garnered attention by England's youth squads for Wharton, as he has already featured for both Under-19 and Under-20 sides.
Progress is likely to have been made early on Tuesday, considering Tomasson's words in the aftermath of their 4-1 win on Monday.
The Blackburn boss said post-match: "There was a bid which the club said no to, which I think was a good choice."
Despite that comment though, Tomasson still appeared quite reserved to the fact that Wharton may still depart the club this month.
Tomasson continued: "There is a chance he could go away. That's football. That's life. One thing we can say about Adam is that we are proud of him if he plays here or if he plays for another club.
"If a player should get an opportunity to play Premier League football then of course it is a difficult choice."
With Palace short on midfield options following the season-ending injury to Cheick Doucoure, the club have been in the market for reinforcements this month.
Doucoure snapped his Achilles tendon in their defeat away to Luton Town back in November, and is highly unlikely to feature again this season.
That has left under-pressure manager Roy Hodgson short on options in the middle of the park, with Will Hughes, Jefferson Lerma and Naouirou Ahamada the only senior midfielders currently fit.
Palace have been boosted by the return of Michael Olise in their must-win encounter at home to Sheffield United this evening though, as another defeat could well end Hodgson's tenure at the club.