It is understood the 37-year-old banked the eye-watering figure as soon as the second year of his contract kicked in last month.

The clause was written into the deal he signed for his Old Trafford homecoming.

“The contracts all renew at the start of July and then the news about Cristiano wanting to leave came out,” a source said.

Ronaldo was forced to take a huge pay cut after he arrived from Juventus, so the Red Devils sort to compensate him by inserting a number of annual bonuses.

However, the payment is not an outright loyalty clause, with image rights and goalscorer bonuses also making up a portion of it.

United are no strangers to agreeing annual payments, having also thrashed out the same arrangement with former players Paul Pogba and Alexis Sanchez.