Ayoze Perez was lost for words after Newcastle United’s agonising defeat at Old Trafford.
Rafa Benitez’s side, dominant before the break, were leading Manchester United 2-0 with 70 minutes gone.
But a free-kick from substitute Juan Mata sparked a late comeback from the home side.
Anthony Martial levelled, and a 90th-minute winner from Alexis Sanchez kept Jose Mourinho in a job.
Winless Newcastle are second-bottom of the Premier League with just two points from eight games.
Perez and his team-mates left the pitch not knowing how they had not taken something from a game they had dominated for 45 minutes.
I thought we did a good job, but the truth is that at the end, we come away with nothing. And that’s the most important thing.Ayoze Perez
“I don’t know what to say after that,” said 25-year-old Perez, who set up Kenedy’s opening goal.
“It was a great performance and a very disappointing result.
“I thought we did a good job, but the truth is that at the end, we come away with nothing. And that’s the most important thing.
“What is so frustrating is that we could not have been in a better position than we were – 2-0 up at Old Trafford with not a lot of time left. We won’t have a better chance than that.
“But they pushed a lot, and, at the end, it felt like they had four or five strikers on the pitch.
“It’s quite hard when you’re facing that.
“Perhaps, in certain situations, our understanding of the game has got to be better.
“For so long, we did a great job out there, dominating Manchester United in the first half.
“But it’s the little details that are still happening. That is what cost us. Against this team, in this situation, you cannot afford to make the smallest mistakes, because they can make the difference.
“Even in the second half, when they were much improved, we still had the chance to score again.
“We could not have given anymore. But the understanding of the game must improve. When you’re 2-0 up, you must look after the result and we did not do that.”
Newcastle haven’t won in nine league and cup games this season.
Perez, however, maintains that the team still has confidence and belief going into the two-week international break.
“It’s still good,” said the forward. “We came here to play against a top side, and we did that. We were pressing, good counter attack.
“The feeling is that we played well, but that was not enough. They scored one more goal than us.
“In the end, they had to put all their forwards on. We should have handled it better and got the result we so desperately wanted”
Referee Anthony Taylor failed to spot a handball from Ashley Young in the first half.
Young handled a free-kick from Jonjo Shelvey.
“I did not see because of the wall, but I felt we should at least have had a corner,” said Perez.
“But, forgetting about that, we were 2-0 up and heading for a magnificent result. We knew they were in a difficult situation, so it’s just a pity we come away with no points.”
Are Newcastle now in a relegation battle?
Perez said: “There’s still a long way to go. We cannot afford to panic, especially after a performance like that.
“We realise we need a win and more points. It’s about improving the details, then we can change.”
Benitez and his players met own Mike Ashley – who was at Old Trafford – for a meal last week.
“We’re trying to create that togetherness as much as we can,” said Perez.
“The spirit is good, but we have to stick together, train hard, keep going, keep pushing.
“Today was a step up, but, against a top side, it was not enough.
“The most important thing is we all travel in the same direction, keep pushing, all together, the most important thing is that we all stay together.”
Newcastle’s next game is against 13th-placed Brighton and Hove Albion at St James’s Park on October 20.
“In two weeks, it’s a big game,” said Perez. “We must beat teams like that.”