Arsenal manager Arsene Wenger believes West Ham United were more prepared for the season opening clash than his side.

The Gunners suffered a 2-0 home defeat against the Hammers and Wenger believes Slaven Bilic's East Londoners were better prepared due to their participation in the Europa League qualifiers.

"West Ham were a bit ahead of us because they had played many competitive games," he said.

"Preparation is preparation, you never get that same intensity, but overall well done West Ham and we have to keep our focus."