''Two weeks ago, I was the king of Manchester,'' Van Gaal said. ''Now, I am the devil of Manchester.''
After opening the English Premier League season with a 2-1 home loss to Swansea, the pressure is already on United and its manager ahead of a trip to Sunderland on Sunday. However, Van Gaal's list of absentees is growing, with Marcos Rojo - signed on Wednesday for 20 million euros ($27 million) from Sporting Lisbon - unavailable as the Argentina defender has yet to receive a work permit.
Central midfielders Ander Herrera, Marouane Fellaini and Michael Carrick were all ruled out of contention by Van Gaal on Friday, along with wide midfielder Jesse Lingard. With Luke Shaw still out with a hamstring injury, Van Gaal cannot call on his three big summer signings - Rojo, Herrera and Shaw - who cost a combined $77 million.
The only piece of good news for Van Gaal is that striker Robin van Persie is available this weekend after being given extra time off to recover from his exertions with the Netherlands at the World Cup in Brazil.
Van Gaal is already pleading for patience from United's fans, who saw the team slump to a seventh-place finish in May in a tumultuous season under David Moyes.
''It shall be difficult in the first three months,'' Van Gaal said. ''I have said that to (executive vice-chairman) Ed Woodward and (owners) the Glazer family.
''I am hired to build up a team and that is a process, and that process needs time. You have to believe in the philosophy that we make again a big club but it needs time and it's not an overnight job.''
Reacting to comments by former United midfielder Paul Scholes, who said this week he was ''genuinely scared'' about the club's future, Van Gaal added: ''I can imagine that fans are also scared. Because they have seen what happened last year and they have seen the first match (this season).''
Rojo was presented as a United player Friday, with Van Gaal saying he had been ''enchanted'' by the left-sided defender's performances for Argentina during the World Cup.
Argentina beat Van Gaal's Netherlands in a penalty shootout in the semifinals.
''My philosophy is that you have to buy only players who fit in the profile and I think Marcos fits in the profile as a left central defender but also as a wing back,'' Van Gaal said. ''He played a fantastic world championship, so I am very pleased.''
Van Gaal had no news about any more incoming players at United before the transfer window shuts on Sept. 1, and refused to confirm or deny reports that England striker Danny Welbeck has been told he can leave the club.
''I do not speak about that because that's private,'' Van Gaal said.