The Japanese playmaker will next month complete a move worth up to £17million to Borussia Dortmund, once he passes a medical and obtains a work permit.
The signing of Kagawa, 23, comes less than a week after United revealed they had doubled their global fan base to 659 million — with almost half of those in Asia.
But Reds’ commercial director Richard Arnold insisted: “We don’t sign players to sell shirts. We are reliant on 25 players and they are all massive stars.
“When you look at the success we’ve seen in that part of the world, it isn’t down to any one player or person.”