Arsene Wenger refused to criticise Petr Cech after the goalkeeper endured a difficult debut in Arsenal's 2-0 loss to West Ham.
The former Chelsea stopper was arguably culpable for both of the Hammers’ goals that condemned Arsenal to a surprise defeat.
However, Wenger insisted it was a "collective lapse" that saw his side concede the opening goal and felt very few Arsenal players put in convincing displays.
"I haven’t spoken to Cech," he said. "The first goal was a defensive lapse - a collective lapse. The concentration maybe was not completely there on the set-piece, the organisation was not perfect.
"We were too far from our goal. We gave him too much distance to run into. We killed ourselves. With the experience we have in our team, it’s difficult to understand.
"I can't see many individual convincing performances today so it's difficult to single one out. Our passing was not incisive enough. Today we have to look at ourselves. We were not good enough."
For his part, Cech seemed to accept that he was at fault for at least one of the goals and took to Twitter to own up.
"First game like this was not in the script - mistake and no points but tomorrow is another day to get ready for the next game! #COYG," he wrote.