The Gunners dominated for much of the game, but they were unable to prevent United’s counter-attacks.
Mikel Arteta’s decision to make a number of changes and form a very high line after United’s second of the day also cost his side any chance of mounting a comeback.
Following the game, Gabriel Jesus has urged his team to learn and improve from the loss:
“The feeling is frustration, because we control the game and were better than them,” said Jesus. “And then we just concede. But now is the time to learn from it and improve. We are doing so well this season, but there are still things to improve for everyone. Everyone is together and we stick together until the end, and that’s it.
“We came to play against a strong opponent and it’s always hard, it’s the Premier League. So we are not happy, because we played so much better [than United].
“But that’s football, if you don’t go there and kill, you are going to have a big problem — and that’s what happened today.”
Arsenal’s first chance to bounce back from the United defeat comes on Thursday evening.
Arsenal will take on Swiss outfit FC Zurich in their first Europa League game of the campaign.
The north Londoners are likely favourites to pick up a win, despite being away from home.
As well as Zurich, Arsenal have been drawn alongside PSV and Bodo/Glimt in Group A.
Given PSV are likely the biggest threat faced by Arsenal, it is important Arteta and co. get off to a strong start before facing the Dutch outfit at the Emirates next week.