Ruben Amorim admitted it was Manchester United's lack of quality that cost them against Nottingham Forest and again reiterated there is no quick-fix.
United were beaten 3-2 by Forest as Amorim lost for the first time at Old Trafford, and are now down in 13th in the Premier League table.
Amorim had only ever lost back-to-back top-flight league games once before in his coaching career. It has not taken him long to experience that at Manchester United
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Highlights of the Premier League match between Manchester United and Nottingham Forest.
Highlights of the Premier League match between Manchester United and Nottingham Forest
He told Sky Sports: "It was a tough game, we started the two halves really bad. It was hard to pass on some calm to the players and continue the game as we should do. We had not a lot of quality but a lot of heart. Suffering two goals after half time in this context is really hard.
"We need more time to put positionings in. If you see the first goal it was good combination between the players and after the first goal we had good moments, creating chances but then we went forward without thinking. It's a tough context but we have to understand this is a long journey and that's what our jobs are."
Nikola Milenkovic headed Forest in front inside two minutes as United conceded their third goal in a week from a set-piece after being overpowered by Arsenal on Wednesday night.
When asked who was to blame for the poor organisation from the corner, Amorim said: "This is more my fault, because I'm responsible.
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MAN UTD DEFENDING CORNERS FOREST SNF
Ex-Man Utd defender Phil Jones picks apart the corner Ruben Amorim's side conceded from after just 91 seconds in the loss to Nottingham Forest
"And we tried to do it in the best way. We did a lot of work in this area, because we saw it in Arsenal. It was really hard.
"In this context, in the beginning of the game, we suffered in the first play. It's really hard to put energy in the team, but we managed to do it. We drew the game [level at 1-1].
"In the second half, the same thing. And then you feel it in everybody. The fans, the players.
"It's really hard to transmit something, like, continue to do your job. We managed to score one more, but then it was more like we wanted, but with not a lot of quality."
United have now suffered back-to-back defeats under Amorim as any new manager bounce hasn't had much short-term impact on results.
Amorim added: "I had this and worse in Sporting in the beginning. I know the feeling for me is the same. For the world it's completely different because you know Sporting is in Portugal, but in Manchester you have a lot of attention, but for me it's the same. The same feeling.
"If you are a little bit experienced in football, this happens with a lot of clubs. And we have to manage to continue to do the same things and improving the team because this will turn around. So we need time and we need to continue to work in the same way every day."
Analysis: Errors undermine Amorim's plans
Sky Sports' Adam Bate:
"Amorim has certainly changed the style of play at United, switching the formation too. They are trying to be more patient but this defeat represents a real setback. There was a noticeable uncertainty, a lack of belief as they chased the game in the latter stages.
"At Ipswich, much of the possession was inside their own half. Here, they were able to edge closer to the opposition goal, having 71.6 per cent of the ball. For context, they only had that much possession once under Erik ten Hag - in a defeat to Crystal Palace.
"But the lack of creativity was alarming, particularly once Fernandes had been withdrawn. United were no doubt stifled by Nuno's impressive game-management too. His cautious substitutions left Harry Maguire with time on the ball. He was unable to use it.
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"Amorim will want to turn United into a team that can dominate the ball with confidence and the example of the first goal - Matthijs de Ligt threading a pass through to prompt the move - will be one that he will point to as evidence that it can be effective.
"But what followed was a reminder that this team is still too fragile, prone to inexplicable errors that can undermine the best laid plans. This job will take time to get right. And their next Premier League game is the Manchester derby at the Etihad Stadium, live on Sky Sports."