He admitted to being frustrated at his team's inability to hold on to a lead - a problem which has troubled the Londoners throughout this campaign.
"It is disappointing because we had the lead and we were 3-1 up and I feel as well that we scored a goal that was not offside," Wenger said.
"But with an average performance we wouldn't have come away with a point.
"We played the game how we wanted to play but we dropped physically in the second half and you could see that the Liverpool game had a baring on tonight's game."
Wenger also apportioned some of the blame on young goalkeeper Wojciech Szczesny, who came off his line to clatter into Aaron Lennon and concede the 70th minute penalty which Rafael van der Vaart drilled home to seal the draw.
"He was a bit late," the Frenchman said.