Manchester United are in advanced talks to sign Newcastle United captain Bruno Guimaraes for around 80 million euros, but renewed interest from Real Madrid threatens to complicate the proposed move, sources close to the negotiations have told Reuters. 

Newcastle's heavy Champions League elimination by Barcelona has paved the way for the Brazilian midfielder's possible departure, with Manchester United targeting the 28-year-old as a replacement for Casemiro, who has already announced he will leave the club.

Casemiro has personally recommended Guimaraes as his ideal successor, citing his experience and leadership, according to the same sources, according to Reuters.