Ex-Manchester United defender Gary Neville has urged fans to give David Moyes time to build his own legacy at the club before being judged.
Moyes is yet to take charge of his first Premier League game at Old Trafford, but has come received criticism in some quarters for failing to sign new players before the season gets underway.
Neville believes that Moyes deserves the chance to fight for trophies at United over a prolonged period of time, pointing to the example set by Arsene Wenger's 17-year stay at Arsenal.
He told The Guardian: "Everyone seems to be talking about David Moyes with a glass half-empty approach. It's as if people are expecting a major drop and they're dismissing the fact that their players are champions who won the league comfortably last season. David Moyes is a workaholic who has earned his opportunity. We should wait and see.
"Manchester United are not reactive. They have a plan in place. David will be given so much time to develop the club. People are saying they're third favourites and Moyes will be under pressure if they lose to Chelsea or Liverpool. Hang on a minute. We need to stop being so immediate. He's got to have time to build his own team and that should be the same at every club. If Jose Mourinho doesn't win the league does that mean he's hopeless? Or Manuel Pellegrini at Man City? We should have a race over three years, not three months.
"Arsenal are doing it brilliantly. The noise around Arsene Wenger these last three years has been immense. But Arsenal stay strong. They're saying: 'No, we're supporting our manager. We believe in him'. From that, I gain confidence there is still some sanity in football."
The Scot begins his maiden league campaign with United on Saturday against Swansea City at the Liberty Stadium.