Ruben Amorim says Manchester United are "soft" defending their own box, adding there is little time afforded at the club to find consistency and wins - so they must happen now.
At Nottingham Forest on November 1, Man Utd conceded twice in two minutes at the start of the second half. They went on to draw 2-2, the same result they had against Tottenham the following week.
Against Everton on Monday Night Football, David Moyes' side - who played with 10 players for most of the game - scored with their only shot on target to beat Man Utd 1-0.
This season, Amorim's side have scored and conceded the same amount of goals - 19 each - and the head coach has criticised his team's defensive play.
Speaking ahead of Sunday's Premier League game against Crystal Palace, he said: "We have some results of not letting a lot of teams in the final third, but we are being really soft near the box so we need to improve that.
"Especially against Forest - we took a lot of crosses, we didn't press well in that moment. Against Everton, they had 10 men, we cannot suffer a goal but we suffered a goal with the only shot on target.
"We are there near the box, we have more players than Everton, we should be better. More strong on the duels and Crystal Palace are very strong on duels and when they have to defend, they are really strong.
"Those things can change how you see teams, but we need to improve in a lot of things. We need to close our goals because we are scoring goals. It's an issue, it's not about the defenders, but about the team and the way we feel our danger near the box.
"It's not just the numbers. It's Nottingham Forest, to suffer two goals in two minutes after half-time, that's a concern.
"You are controlling the game against Tottenham and you have the same amount of guys when they score. We are in a good position, but we need to be better and more aggressive. That is my biggest concern.
"It's the way you see the game and understand that if you're better in this moment, you should have more points and the narrative will be different."
After a run of three successive Premier League wins, Man Utd have not won a league game in November, and will be hoping to put this right at Selhurst Park this weekend.
Amorim also pointed out that the pressure to win at Man Utd is more intense than at any other club, and it will take time to find consistency with wins - something not afforded to many.
He added: "I think it's clear it will take time especially in the Premier League when every club is prepared for everything. They are improving a lot.
"We need to win now. If not, something is going to change and we know that. We just need to be better.
"Look at our games - could we have won last game? Yes. We had everything to win it. Same thing against Forest, they were suffering, we had three unbeaten and we didn't win. Tottenham the same.
"It's the urgency of winning. It's not good to be at United and not winning - there is no time here. That's why I'm frustrated all the time. We know we need time, but there is no time here so let's do everything to win games."
There were also questions over Kobbie Mainoo, who is yet to find himself with a regular starting spot at Man Utd. He was one of England's shining lights at Euro 2024, but his lack of game time at club level has seen him on the periphery of contention for next summer's World Cup.
On Monday, he played half an hour against Everton, and while Amorim does not rule him out as a starter in the future, his focus is on positive results.
"This is a team sport. I have a lot of players in my squad, they want to be in the World Cup," he said.
"I put Kobbie [on against Everton] because he's really good near the box. Between Bruno [Fernandes] and him, he can find spaces near the box and score goals so that was my idea.
"I will use Kobbie and the rest of them to try and win. I'm not focused on one individual, I'm focused on all my players and I know how special it is to play at a World Cup.
"My job is to win as a team and focus as a team. Kobbie Mainoo is in the same situation as the other guys - if I feel that's best to win the game, I will do it.
"I see him as a starter like the other guys. I just have to make a choice and in the end, it's not been Kobbie. In the future, I don't know. I just want to win games, I don't care who is playing."
