Arsenal boss Arteta questions officials for allowing Brentford equaliser

“You have to apply certain principles in defending and you do that by sticking to the rules. Suddenly you change the rules and then you have to change your principles.

“So tell us before so then you don't hold the (defensive) line that high. Because you're always going to have an advantage if you get blocked. You cannot block if you are offside.”

There was also a suggestion that Norgaard was offside before he made the assist but that did not appear to be proven.

Asked about the equaliser, Brentford manager Thomas Frank said: “I agree that when they kick the ball Ethan is in an offside position.

“As far as I know the football law, the next question is, did he influence that we could cross the ball across? They decided it was not enough, I agree!”

Arsenal have 51 points, six more than second-placed Manchester City, whom they host on Wednesday.