AC Milan midfielder Brahim Diaz has an anti-Manchester United clause in his contract.
La Gazzetta dello Sport says Diaz is said to have a clause in his Real Madrid contract that makes a move to Old Trafford undesirable.
The attacking midfielder moved to Los Blancos from Manchester City in 2019, and an 'anti-Man Utd' option was included in the deal.
The Italian publication states that if Real were to sell the Spaniard on to United then City would be owed a whopping 40% of any transfer fee.
Brahim is currently on loan at AC Milan for a third consecutive season, and scored twice in Saturday's 4-1 win over Monza.