United's only signing during the European summer transfer window was Marouane Fellaini from Everton, with the reigning English Premier League champions reportedly missing out on the likes of Cesc Fabregas, Thiago Alacantara and Ander Herrera.
But United's director of communications Phil Townsend said the club achieved what it set out to during the transfer window, as they also retained Wayne Rooney, who had agitated for a move to Chelsea.
"The club had two main priorities for the transfer window," Townsend said in a letter to United supporters.
"The first was to keep Wayne Rooney.
"He is a world-class player and the manager is very keen to have Wayne as a key part of the club's drive to retain the Premier League trophy. That aim was fulfilled.
"The second priority was to add a midfield player and the capture of Fellaini has met that need."
The lack of transfer activity sparked plenty of criticism of both United and their new manager Moyes but the Manchester-based club have argued their future cannot be shaped in 'an eight-week panic'.
"The club has demonstrated its commitment to David Moyes in the award of a six-year contract," Townsend said.
"Allowing him to shape the future Manchester United team is a long-term project not an eight-week panic."
