The England international striker left Old Trafford for £16 million on transfer deadline day, while the likes of Angel Di Maria, Radamel Falcao, Daley Blind and Marcos Rojo have all been added to the United squad in recent weeks.
The situation attracted criticism from former player and assistant manager Mike Phelan, but new coach Louis van Gaal's deputy Ryan Giggs - who formed part of United's fabled Class of '92 - says the club's traditions remain intact.
"United will never change," he stressed at the Soccerex convention in Manchester. "The history of the club is to play exciting football, give youngsters a chance and keep to its traditions.
"Okay, Danny Welbeck has left, which is disappointing, but this is a manager [Van Gaal] who gave Clarence Seedorf, Patrick Kluivert, Xavi, Andres Iniesta and Thomas Muller their chances.
"Tyler Blackett has played every game so far this season. We have Adnan Januzaj and James Wilson.
"Players will leave but we have to make sure youngsters come through. United fans demand it.
"We are proud of our youth system - that is what we feel separates us from a lot of other clubs - we always give young players a chance.
"I hope another Class of '92 comes through but the world is changing, and the young players coming through now might not be from Salford, even if you wish they were. They might be like Rafael da Silva from Brazil who has been with us from the age of 15."
United will be looking for their first win of the season against QPR on Sunday.
