The Gunners were out of action in attack with the absence of Pierre-Emerick Aubameyang and Alexandre Lacazette who all missed the game with illness.
Arsenal, ending last season on a high note with four wins couldn't shined in their first game of the season as they failed to stand the high pressing football from newcomers Brentford.
The Bees drew first blood through Sergi Canos in the 22nd minute before extending their lead in the 73rd minute, thanks to a Christian Norgaard's strike.
Arteta being disappointed with the result pleads to the fans as he ruled out any panic buying in this summer.
"First of all, thank you because of the support that they are giving to the team, the travelling fans that were here,’ Arteta told reporters at his post-match press conference.
"And after that, I apologise for the result and we know that we have to improve.
"We have two big games coming up right now and we need to a different performance to get a different result.
"We are very disappointed to start the way we did in the season.
"We didn’t get the result or performance that we wanted.
"My focus is with the players we have, try to make them play as best as possible and get the best out of the team and find a way to win football matches,’ he went on.
"We are very clear of what we wanted to do, where our strengths are and where we can improve and I don’t think today’s performance shows anything different to what we’ve already seen."
