Casemiro has been on the lookout for a new club since the start of the year, with United deciding against renewing his contract which is due to expire at the end of the season.
The Red Devils confirmed the decision in January, with a statement reading: "Casemiro will leave Manchester United this summer, upon the expiry of his contract.
"The legendary midfielder has enjoyed four seasons at the club, playing 146 games and scoring 21 goals to date.
"A serial winner, Casemiro was unveiled at Old Trafford in August 2022, and quickly became a fan favourite due to his combative nature and ability to score goals at crucial times."
He has remained a key player during the club's resurgence under Michael Carrick, putting in trademark performances in wins over the likes of Manchester City, Arsenal, Fulham, Tottenham Hotspur and Everton over the past month or so. The 34-year-old had previously been derided by fans and pundits alike, looking particularly exposed during the latter stages of Erik ten Hag's spell in charge and most of Ruben Amorim's brief stint.