United have now won just two of their first seven Premier League games of the season.
Manchester United manager Ole Gunnar Solskjaer encouraged his forward players to learn from the killer touch of Pierre-Emerick Aubameyang after the Arsenal striker secured a 1-1 draw for the Gunners at Old Trafford on Monday.
United have now won just two of their first seven Premier League games of the season and again paid for their inability to convert their chances other than a long-range strike from Scott McTominay just before half-time.
Solskjaer's side have failed to score more than once in any game since the opening day of the season.
"We go 1-0 up and then we don't get the second goal that we want to get. That's the learning now for this time," said Solskjaer, whose side are languishing 10th in the table.
"Be more cynical, clinical. There are so many games we have been 1-0 up.
"We will learn. We are at the start of building something. It's just a bit disappointing that we can't get that second goal."
Aubameyang was not even distracted by an erroneous offside flag that initially ruled his goal out just before the hour mark.
However, the goal was given after a VAR review with the Gabon international clearly played onside by Harry Maguire.
Aubameyang has now scored eight goals in eight games this season, including seven in the Premier League.
"Seven now in seven games, so that's clinical," said Solskjaer admiringly of Aubameyang.
"You think at the time maybe Harry managed to get out but it was a few yards onside and a good finish."