"We had a game where nothing was really happening for us and everything was happening for them," Cech told the club's website (www.arsenal.com).
Wenger blamed bad luck and a refereeing error in the build up to the second goal for the defeat but the Czech goalkeeper said it was hard to pinpoint exactly what went wrong.
"We made more mistakes and with the possession we had in the second half we didn't seem to find the right passes at the right time," Cech said.
"We lacked efficiency. Football is about scoring goals and we couldn't find our chances... and we got punished for it."
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Saturday's match was the first in 11 that the Gunners had failed to score and the first in the league this season in which Arsenal had conceded more than two goals.
"The positive thing is there is a game on Monday and we will be ready to bounce back," the former Chelsea keeper added.
Arsenal take on a Bournemouth side that are unbeaten in their last six league fixtures, a run that includes high-profile wins against champions Chelsea and Manchester United.
One Arsenal player who is certain to miss the match is midfielder Jack Wilshere. The 23-year-old has been out with a fractured fibula since early August and is now not expected back until February at the earliest, according to his manager.
(Reporting by Chris Peters in Bengaluru; Editing by John O'Brien)
