The Trafford Training Centre, or Carrington as it's known by players, staff and fans, will become the Aon Training Complex from 1 July, a partnership that points to the investment made in United's training facilities.
But it is the recent revamp of Carrington, including new medical and sports science facilities, that Sir Alex feels is a significant addition to the club.
Speaking to Inside United in his regular monthly interview, Sir Alex says: "As I said last year, it could be our best signing. It's working out at about £20million that we've spent, but it's given us a training facility where all the players are saying, 'Wow, this is some training ground now.'
"It's one of the best. And I think if any player were to come here with any doubts about where they should be, they'll soon find out that this is a fantastic set-up."