Manchester United is making headway in signing Casemiro, who is now a transfer window priority.
Carlo Ancelotti and Real want the Brazilian to stay in Spain, but the player and club have mutual respect.
European champions say they won't stop Casemiro from departing if he wants to and if his worth is reached.
United could sign the 30-year-old for £50m if he agrees to personal terms, but the total could top £60m if add-ons are agreed.
United, though, is speaking with Casemiro's agents to make sure that the midfielder is interested in a move to Old Trafford.
United would pay Casemiro close to £400,000 per week, including bonuses, throughout these talks.
It is believed that United is willing to grant the player a five-year contract, an attractive choice for a player beyond 30.
United is unable to provide Champions League play. They would seek financial incentives to overcome this obstacle.
Before the transfer window closes, Erik ten Hag aims to acquire five new players, with defensive midfield as a top priority.