Arsene Wenger claims his young Arsenal players were rocked by a World Cup hangover at the start of the season.
Fledgling players such as Cesc Fabregas, 19, Philippe Senderos, 21, Johan Djourou, 19, and Theo Walcott, 17, were among those on international duty in Germany.
Wenger said: 'We were disturbed by the World Cup. We had a lot of very young players away and it took them a lot of time to recover.
'Then, the international schedule has gone completely crazy. I never saw the players.
'This is the first week I have had with them since the beginning of the season.
'I told them to be faithful to the way we want to play. We do not have to question the way we play, we have to do what we do better.'
Arsenal started the Premiership season with two draws and a defeat but stopped the rot with a 1-0 win at Manchester United on Sunday.
Emmanuel Adebayor's late winner was created by Fabregas, who looks to have recovered from his busy summer with Spain at the World Cup.
Wenger said: 'Fabregas was absolutely outstanding. He did not stop from the first minute to the last.
'His passing was fantastic. He defends, he attacks. In the last five minutes, he was still in the box. He was amazing.
'But I think every player did well. We have shown a lot of mental strength.
'There were a lot of questions raised about us and our team spirit.
'We missed a penalty, which is effectively like being 1-0 down, but we came out in the second half and won the game.
'It tells you a lot about the spirit and the mental strength of the team.'
Adebayor, 22, was another Arsenal star on World Cup duty and he believes the win at Old Trafford will kick-start the season for the Gunners.
The Togo striker said: 'I hope this is a breakthrough for the team. We never got down. We were never out of the race.
'We needed this win and we showed we are a good team. We showed we can play good football. We showed we enjoy playing as a team and working for each other.
'It was a very important game, we won it and I think confidence will come back a little bit.'
Adebayor joined Arsenal for £7million from Monaco in January and scored four times as they made a late charge to finish fourth in the Premiership.
The 86th-minute winner at Old Trafford, however, shoots straight to the top of his list of favourite goals.
Adebayor, who also earned a first-half penalty which Gilberto missed, said: 'It was the important goal I've ever scored.
'I knew all the fans were watching this game and I had not scored in the Premiership this season.
'I got my chance to play. I enjoy the way Arsenal play and it was important for us to win our first game.
'Now I hope we are going to win a lot of games at home. We have to focus on our next game.'