The Gunners had a 2-1 lead at half-time against Blackburn on Saturday, but ended up losing the game 4-3.
Arsenal have just four points from five games in the league this season and the Gunners have also conceded 14 goals.
“It is terrible, it is just not good enough. Of course we are very frustrated, the spirit in the team is quite willing but if you look at the number of goals we have conceded that is not good enough,” Wenger admitted.
“You cannot come here and concede four goals the way we did today.
“On the other hand I believe that the group will take off but it’s important that we get quick results.”
“Speculation is part of modern life, what can I do about that?” he said. “My future is focusing on what I do well and that means giving my best for the club. I have no influence on the speculation.”
He added: “You cannot say you have no worry when you see the performance we have put in today. It’s just not defensively solid enough when you are 2-1 in front against Blackburn and you know if you are solid enough defensively you will score goals.
“It’s not all negative today, that’s ,in fact, the frustrating thing as well. At the moment we do not have the capability to focus defensively to win games like that. It is important you do not give cheap goals away like that.
“Overall we created many chances, even in the second half but we had a lack of focus on what we knew they were strong at – corners, free-kicks.
“Overall we lost a game where we scored six goals and that’s quite disappointing.”
