Manchester United must hire a top-five sporting director as soon as possible, according to the editor of the club's fanzine United We Stand.
Ed Woodward has expressed his desire to hire a former player to fulfil the role, while legendary manager Alex Ferguson wants to see Steve Walsh employed in a consultancy role.
According to Mitten, a candidate with experience should take top priority.
"It has to be an excellent sporting director - someone who knows how to do that job better than anyone else, a top-five person in the world," Mitten told Sky Sports.
"These people tend to speak five languages. They tend to be football obsessives. They tend to know that there is a brilliant left-back at Palermo and know his agent and know a club has already been onto him. They have got a rich depth of knowledge.
"There are a lot of talented people at Manchester United on the recruitment side. There are a lot of people with world-class CVs but the end result is that players are coming in and it is not gelling.