United were widely condemned for their transfer business over the summer.
Both Moyes, and particularly executive vice-chairman Ed Woodward, were criticised when Marouane Fellaini ended up being their only signing.
Some supporters were irritated enough to write to the Old Trafford outfit and demand answers.
And under the fans' charter, established by the Premier League and which United adhere to, director of communications Phil Townsend wrote back to explain the club's thinking.
"The club has always backed the manager in the transfer market, as Sir Alex (Ferguson) has said on many occasions and it will continue to do so," said Townsend.
"The club has demonstrated its belief in, and commitment to, David Moyes through the award of a six-year contract.
"Allowing him to shape the future Manchester United team is a long-term project not an eight-week panic.
"He must be given time to assess his new squad and come to his own decisions on which players he feels will strengthen it."
Indeed, as Townsend also pointed out, and United stressed privately immediately after the window closed, there has been a reshaping of Moyes' squad, and two of the most immediate priorities were met.