Manchester United boss Erik ten Hag admitted that his side are still "fragile" despite Sunday's 2-1 win over Luton Town.
Danish striker Rasmus Hojlund scored an early brace to help Man United claim a fourth consecutive Premier League victory.
The 21-year-old opened the scoring inside 36 seconds to become the youngest player to score in six straight Premier League matches.
Hojlund quickly doubled the visitors' advantage, before Carlton Morris pulled a goal back in the 14th minute to give Luton a foothold.
As it proved, there were to be no further goals in the contest, as both teams missed chances to add to their respective tallies.
While Man United are unbeaten in seven competitive games, Ten Hag believes that his side can still improve upon their performance at Kenilworth Road.
Ten Hag told reporters: "Fragile [at times], because we didn't take the chances, I think we should have scored many more goals. After 2-0 there were big chances for Rashford and Garnacho, it could have been 3-0, 4-0.
"We dropped too deep and we allowed them some crosses and a lot of shots and some chances. After half-time they of course upped the pressure. We missed some really massive chances and we should of scored and we know that.
"On the other hand, Luton Town have lost games this season, but only two times by more than two, so it is not easy here. Apart from last week their performances and their results are very good.
"The way we started was perfect and that's the way we want to do it, it was a perfect game plan but the only thing we didn't do is be more clinical in front of goal. We must score more goals because today we could have easily scored five goals."
The Man United manager was full of praise for Hojlund, who has scored seven goals in his last six top-flight appearances after failing to find the net in any of his first 14 Premier League matches.
"We are very happy with our recruitment," Ten Hag added. "But we need the right characters because he can perform under stress. When things go against him like in the first half of the season, he has the abilities and the character to be resilient. He is determined to score goals and that is what we scouted him.
"He needed some support, as it is not easy when you are young. But in general, he kept calm and you can see his abilities. I want to also mention that in the start he didn't have some luck.
"He scored some goals, for instance, the one against Brighton and it was disallowed and nobody knows why. Those moments are important, especially when you come into a new league, especially for a striker to build some confidence. He is a fighter and he keeps going and he has great abilities in front of goal."
Man United finished the weekend in sixth position in the Premier League table, with three points separating them from fifth-placed Tottenham Hotspur, while they are five points adrift of Aston Villa in fourth spot. body check tags ::