United approached the game encouraged by a pre-season campaign in which they won five and drew one of their six matches, notably beating Real Madrid and Liverpool, but at Old Trafford on Saturday, the old failings returned.
Despite enjoying 60 percent of possession, there was no cutting edge to United's play, and both Ki Sung-yueng and Gylfi Sigurdsson were afforded acres of space when they scored the goals that gave Swansea a 2-1 win.
"We have built up a lot of confidence," Van Gaal said afterwards
"It will be smashed because of this."
The 2013-14 campaign was a long succession of unwelcome milestones for Van Gaal's predecessor, David Moyes, and the Dutchman was quick to add one of his own: United's first opening-day home defeat in Premier League history.
It moved former Liverpool midfielder Steve McManaman, now a television pundit, to declare Van Gaal's team "the worst Manchester United side I've seen for 20 years".
In mitigation, Van Gaal could point to an injury glut that deprived him of the services of Jonny Evans, Michael Carrick, Antonio Valencia, Danny Welbeck, Robin van Persie and new signing Luke Shaw.
With untried youngsters Tyler Blackett and Jesse Lingard in the line-up, United looked uncertain in Van Gaal's favoured 3-4-1-2 formation and at half-time the manager abandoned it, reverting to a 4-2-3-1 shape.
But although United equalised through new captain Wayne Rooney, Sigurdsson soon restored Swansea's lead and the hosts' attempts to find a second equaliser were incoherent.
Juan Mata was largely anonymous, despite the fact that United's new system is designed partly to give the Spanish playmaker optimal conditions in which to work.
And with Marouane Fellaini -- gangling symbol of Moyes's failures -- thrown on to chase high balls into the Swansea box, the final stages of the game resembled the darkest days of the previous campaign.
- 'We will learn' -
"You can see during the game the United players were thinking about where they had to be," said former Netherlands international Ruud Gullit, analysing the game for the BBC.
"When he (Van Gaal) played 3-5-2 for the Netherlands it was necessity because we had bad defenders
If you were a Swansea player, would you have been afraid of that line-up?"
Having lost stalwarts Ryan Giggs, Nemanja Vidic, Rio Ferdinand and Patrice Evra since last season and signed only Shaw and Ander Herrera, there is a pressing need for new blood that United have only two weeks to address.
They have been linked with Argentina defender Marcos Rojo and Roma's Moroccan centre-back Mehdi Benatia, while British newspaper reports on Monday claimed a £100 million ($167.3 million, 125 million euros) package was being prepared to lure Angel di Maria to Old Trafford from Real Madrid.
After seeing Moyes and incoming executive vice-president Ed Woodward miss out on a string of high-profile targets a year ago, United's fans will observe the final fortnight of the transfer window with bated breath.
United's ability to strengthen their squad could go a long way towards determining the shape of their season, but Rooney is convinced that in Van Gaal, at least, they have the right man to take the club forward.
"This is a really bad result for us, but we will learn, especially with the manager we have got," said the England striker.
"He is strong and he wants 100 percent every game
We know last season was a disaster
It wasn't good enough and we were ready for the start of this season.
"Maybe after a good pre-season we were a bit over-confident
But we just have to look at the bad points and cut them out
If we do that we will win games."
Source : AFP
Source: AFP