The 32-year-old has again been an important player for the Red Devils during the 2023-24 campaign, making 29 appearances in all competitions, scoring five goals and registering three assists in the process.
However, the Brazil international's performances have been widely criticised, especially against Crystal Palace on Monday night, when he struggled in a 4-0 loss for the Red Devils.
Casemiro has another two years left to run on his contract at Old Trafford, with the option of an additional 12 months, and there is not expected to be European interest in the midfielder this summer.
However, clubs from Saudi Arabia are believed to be keen, and according to CaughtOffside, Al-Nassr have 'accelerated their interest' in the South American.
Al-Nassr 'pushing to secure Casemiro's signature'
The report claims that representatives from the Saudi Pro League outfit have held talks with Casemiro's agents over a move to the club this summer.
Casemiro is Man United's highest earner, but he would be able to pick up an even greater salary by making the move to Saudi Arabia, and the midfielder is said to be open to a fresh challenge.
Al-Nassr famously signed Cristiano Ronaldo following his departure from Man United, and the 39-year-old has a record of 56 goals in 60 appearances for the club in all competitions.
Sadio Mane, Alex Telles, Aymeric Laporte and David Ospina are also among the former Premier League players to turn out for the Saudi Pro League team.
Will Man United regret Casemiro exit?
Casemiro was excellent for Man United during the 2022-23 campaign, but there is no getting away from the fact that he has struggled this season.
A lack of structure around the Brazilian has not helped, but he has struggled with the pace of the Premier League this term, and it is difficult to see him staying at Old Trafford this summer.
An exit would see Man United remove a huge salary from their budget, and his transfer fee could also be reinvested in the squad, with at least one midfielder expected to arrive.
A move to Europe is unlikely, but clubs from the Saudi Pro League have the funds to sign him, and the Red Devils should be looking to move on from Casemiro this summer.
Anthony Martial, Jonny Evans and Raphael Varane are also set to leave the club on free transfers at the end of June, with major changes planned at Old Trafford in the coming months.