Manchester United boss Erik ten Hag urged fans to keep the faith after defeat at home to Brighton.
It means United have now lost three out of their first five games of the season.
Ten Hag said: "We are disappointed and I think it's normal, especially when you have seen the game. Such head to head, such small margins. In the first half, we created a lot of chances but we didn't score and they scored on their second attack, their first chance and we concede a goal. The first 20 minutes was very good. I think we had the chances, in the first half, I think we played very well but we didn't score. We didn't finish.
"In this period, we have to deal with setbacks and the disallowed goal, just before half-time, it was not our day, not our period. We fought back and then we get a goal, or at least we thought we got a goal and then it was disallowed. It's difficult, it's not falling on our side but it will change. The moment before half-time can get you back in the game.
"We have to improve, there are things for the team and the individuals, who have to step up. Sometimes, in those difficult periods, where we are now, you have to face that and you have to deal with that. In this moment, we don't deal well with it but we showed that least year, the resilience and determination, also in defence, as you say."
"You will see the game. Did you see [us at] Arsenal? Did you see [us at] Spurs? They could have been the other way. We have to correct it by ourselves. We can't blame anyone else. We have to do better, be more resilient and be more determined to get these wins."
On fans booing his decision to substitute Rasmus Hojlund, Ten Hag added: "I think it was very good that Hojlund, obviously the crowd embraced his first performance, his first performance at Old Trafford, which is very good, when you bring in a new player and he gets this reception. Everyone is excited by it and I think he performed very well so we are happy. This is the next step, after his injury, he recovered from it. He has some deficiencies in fitness and we have to build that. But I think it was another big step."
