Erik Ten Hag admitted that defeat in his first game as Manchester United manager was a “real disappointment”.
Pascal Gross’ first-half brace gave Brighton a 2-0 lead at Old Trafford and although United threatened a second-half comeback with Alexis Mac Allister putting the ball into his own net from a corner on 68 minutes, the hosts were unable to find an equaliser late on.
“It’s a setback, a real disappointment and we have to deal with it,” he told Sky Sports.
“I knew from the start that it will not be easy and it’s a process. It takes time. But you don’t have time, you have to win games and we should have done better.”
Ten Hag showed little emotion as Brighton took a 2-0 lead in the first half and asked what was going through his head at that moment, the Dutchman responded: “I analyse it. It was unnecessary. We gave two easy balls away and I think in organisation was a big mistake.
“We have to analyse and take the lessons.”
Ten Hag made the decision to start with Cristiano Ronaldo on the bench but he was pleased with the impact the 37-year-old made having been introduced eight minutes after the restart.
The Dutchman said: “It’s clear to see that in the second half we were better in the midfield with Christian Eriksen down and Cristiano Ronaldo up. Then we create and I think [Marcus] Rashford had two really good chances and it’s a pity we didn’t score them to make it 2-2.”
However, Ten Hag stressed that it will “take time” for Ronaldo to be match fit having missed most of United’s pre-season.
“You cannot force it,” he added.
“One week in training, a little bit more now, and he has to do more to get fit. This game will help him, the 35-40 minutes he had now. Now we have one week and he will be better next week.”
Asked his opinion on United’s attack, Ten Hag said: “I’m not satisfied. Totally not happy because we lose and it was not necessary. As I said, we should have done things better.”
Ten Hag was also quizzed if United will do more business this transfer window, but the former Ajax boss did not give a direct answer.
Asked if the challenge has got bigger this season, Ten Hag responded: “No, that’s the same. I knew before, this is not easy to construct it, to build it, to develop this. This takes time.
“But as I’ve said, I know at the top you don’t have time, you have to deliver. We are aware of the situation.”
Before kick-off, the Dutchman stressed that togetherness was the most important thing and asked if he witnessed that during the 90 minutes, he responded: “I said it after the game in the changing room that I see it in the game.
“The reaction in the second half, we are acting as one team, we are battling for [a] better result. I have seen that clear, in also the first half.
“It’s not about that we didn’t battle, it wasn’t that we didn’t have the right attitude, no. We made mistakes on the ball, passing mistakes and organisation mistakes in defending.
“We have to take the lessons and learn quickly from that.”
United captain Harry Maguire also admitted it was a “disappointing result”.
He added: “It was the worst possible start, to be 2-0 down at half-time at Old Trafford – not good enough.
“We huffed and puffed and we got one back and we had chances to equalise, but it’s a bad start for us.
“I think we actually started the game pretty well. We started on the front foot. We conceded a first goal which knocked us back really badly, we stopped playing from then. They got a lot of control in the game, so we need to look at not letting that goal set us back as much as it did.
“But we’ve got to be better on the ball, we gave the ball away too much in the first half. We gave them encouragement to come forward and attack us.
“It was a nightmare start to be 2-0 down at half-time.”
