Manchester United boss Erik ten Hag was furious with Arsenal's second goal in Sunday's defeat.
Jonny Evans appeared to be fouled ahead of Declan Rice's strike in injury time.
Ten Hag said: "I think we deserved to win this game but you don't always get what you deserve.
"I look more at how we step up and if you see from the Wolves game to this game there is big progression. Tonight was a team, I am really happy with this performance and the progress of our performance.
"We did well, we make progress, stick to the plan and believe and in the future we will win games like this."
On Arsenal's second goal, he added: "It can't be that this goal is given. It was a clear foul."