After a difficult summer for the club, United look set to sign the midfielder in a desperate attempt to bolster Erik ten Hag’s squad.
Recruitment staff at Old Trafford have been criticised this summer amid their long-running pursuit of Frenkie De Jong, who is now being linked with a move to Chelsea should he leave Barcelona.
A five-time Champions League winner in the Spanish capital, Casemiro played a key role in restoring Madrid to the top of the European game after returning to the club from Porto in 2015.
In total, the Brazil international made 336 appearances for Real, lifting three LaLiga titles, three UEFA Super Cups and three Club World Cups to go along with his multiple Champions League successes.
Speaking on Friday, Ancelotti said: “I talked to (Casemiro) this morning. He wants to try a new challenge, a new opportunity. I and the club understand it.
“With what he’s done at this club and the person he is, we have to respect it. There are talks right now, nothing is official, but he wants to leave."