Mourinho hinted that he would not bring in a direct replacement, instead restructuring his backroom staff to potentially leave room for Michael Carrick to one day adopt the position, but the 55-year-old has made a U-turn as a new man will now be brought in.
Asked to reveal the identity of his new right-hand man, Mourinho told Record: "It's a person coming who worked with me before but I can't say the name because he's still linked to another club.
"Good coaches there are many, but I like to make my assistants. I do not like trained coaches, I like to shape them in my way of thinking and they grow with me and I also grow with them."
Aitor Karanka, who is currently in charge of Nottingham Forest, is now the favourite to be appointed as United assistant following Mourinho's comments.