The young Belgium international inherits the shirt that has belonged to Ryan Giggs for over 20 years, while Luke Shaw takes the No.3 and Ander Herrera the No.21 jersey
The Belgium international inherits the number vacated by the recently retired Ryan Giggs, who ended one of the most decorated ever playing careers to become Louis van Gaal's assistant manager this summer.
New midfield signing Ander Herrera takes the No.21, while teenager Luke Shaw is handed the No.3 as he succeeds Juventus-bound Patrice Evra.
The club's legendary No.7 shirt remains vacant, having been given up by Ecuadorian winger Antonio Valencia over a year ago, and could yet be filled by transfer target Juan Cuadrado.
There is also no No.9 listed by Van Gaal's side, with newly confirmed captain Wayne Rooney keeping his No.10.
Retaining their squad numbers are the likes of Anderson, Wilfried Zaha and Marouane Fellaini, all of whom have been linked with moves away from Old Trafford this summer.
SQUAD NUMBERS IN FULL:
1. De Gea; 2. Rafael; 3. Shaw; 4. Jones; 6. Evans; 8. Mata; 10. Rooney; 11. Januzaj; 12. Smalling; 13. Lindegaard; 14. Hernandez; 16. Carrick; 17. Nani; 18. Young; 19. Welbeck; 20. Van Persie; 21. Herrera; 22. Powell; 23. Cleverley; 24. Fletcher; 25. Valencia; 26. Kagawa; 28. Anderson; 29. Zaha; 30. Varela; 31. Fellaini; 34. Lawrence; 35. Lingard; 36. Vermijl; 38. M Keane; 39. Thorpe; 40. Amos; 41. James; 42. Blackett; 45. Petrucci; 46. Rothwell; 48. W Keane; 49. Wilson; 50. Johnstone.