Manchester (United Kingdom) (AFP) - Louis van Gaal believes Manchester United's 2-1 home defeat by Swansea City in his first competitive game as manager accurately reflects the enormity of the task ahead of him.
Saturday's 2-1 loss at Old Trafford was the first time in Premier League history that the 20-time champions -- who finished seventh last season -- have lost an opening-day fixture at home.
A spate of injuries forced Van Gaal to hand competitive debuts to two academy graduates -- Tyler Blackett and Jesse Lingard -- and his three central defenders had an average age of 22.
Spanish midfielder Ander Herrera made his competitive debut, but United's only other close-season recruit, left-back Luke Shaw, is currently sidelined by a hamstring injury.
Although he was reluctant to discuss plans to strengthen United's thin squad, Van Gaal conceded that the loss to Swansea would serve as a reminder that success is unlikely to come instantly.
"Of course, I have said that in previous press conferences," said the former Ajax, Barcelona and Bayern Munich coach, who succeeded the sacked David Moyes last month.
"Also, because we won (friendlies) in the United States and we won against Valencia, the expectations are so high. We also saw that in the first half because I saw a lot of players very nervous, making the wrong choices, and that's a pity.
"But, also, players have to be used to that expectation, because this is Manchester United. You have to cope with that pressure, but that is also a process."
Wayne Rooney, installed as captain by Van Gaal, cancelled out Ki Sung-yueng's 28th-minute opening goal with a smart volley, only for Gylfi Sigurdsson to slam home a 72nd-minute winner for the visitors.
It was a stark indication of how much improvement United need to make in their squad, but this was not new intelligence for the manager.
"When we were playing in the USA, I thought the same," said Van Gaal.
"I know what positions we need better players, but you have to buy only when those players can fulfil the way of playing that I ask. We will have to wait and see."
- 'Both systems' -
United will also seek to trim their squad during the remaining two weeks of the transfer window, but Van Gaal said that showing players the door was never a straightforward process.
"No, because I don't think it is only up to me," he said. "It's also up to the players to decide, because we have given a contract to the players.
"I shall talk to the players about what I think, what I expect from them. I never shall say, 'You have to go.'"
Van Gaal saw an improvement in the second half after switching from a back three to a flat back four at half-time and the tactical mastermind believes his players are capable of adapting to his different demands.
"I had these questions from my Dutch friends in the World Cup," said the Dutchman, who led his country to a third-place finish in Brazil. "I think we can do it with both systems.
"You could see in the first half we weren't playing very well. That's why we changed the system and used this system they have always played at Manchester United. Then I changed it again. I did everything to try and win."
Van Gaal also revealed that Dutch international striker Robin van Persie is gaining fitness after his post-World Cup break and could be in contention for next weekend's trip to Sunderland.
Meanwhile, Swansea manager Garry Monk said that he was unmoved by pre-season predictions that his side would face a struggle to avoid relegation.
"I don't care. It's about us, getting ourselves right. What other people say outside the club, I don't care," said the former Swansea captain.
"There will be ups and downs over the season, but hopefully, if I prepare the team correctly, we will have more days like this."