Valencia left United this summer after the club decided against triggering a one year extension, and was announced at LDU last week.
The former captain spent ten years at United since joining from Wigan, winning six major trophies as well as three Community Shields. In all, he made 339 appearances for United, scoring 25 goals and registering 62 assists.
LDU president Esteban Paz told El Comercio that the club will travel to Old Trafford for a friendly game next summer before the start of the 2020/21 season.
He said: “The match belongs to Antonio: the income, the box office. [LDU] will handle the entire external theme. This is the most important product associated with the Antonio Valencia brand.
“Little by little, we will start building Antonio's farewell party at Old Trafford."