Erik ten Hag acknowledged that "indisciplined" Manchester United never recovered from a "very bad start" during their defeat by Tottenham. (More Football News)
The Red Devils suffered their third Premier League loss of the season, as Spurs ran out commanding 3-0 winners at Old Trafford.
United fell behind after just three minutes when Micky van de Ven ran almost the length of the field before crossing for Brennan Johnson to tap home, while Dejan Kulusevski and Dominic Solanke sealed Tottenham's victory in the second half.
And Ten Hag believes his players were deeply impacted by their early setback.
"A very bad start from us. To concede a goal after two or three minutes like that, did something to our belief," he told BBC Match of the Day.
"It was totally unnecessary to concede a goal like this, the [opposing] centre-half stepping in and passing the whole team over the right side, and then the winger tapping in at the far post.
"From that moment on, we were stressed on the ball. We were indisciplined. We could not find the triangles or the switches. We had some good moments, but from that moment, we could not get a foothold.
"We can do better than that. First, we have to deal with this and show resilience. This is not good enough."
United played over half of the game with 10 men following Bruno Fernandes' 42nd-minute red card for a high challenge on James Maddison.
Ten Hag feels the dismissal was harsh, but is confident his players can bounce back from their latest defeat.
"We had chances to come back, and then the red card changed the game," he added. "I don't think it was a red card. It was only 1-0; we could have made a comeback, and it had a big impact on the game.
"There is always a new day, and we will learn from it. My players are strong characters and we will bounce back. We have to learn from this and quickly."
