Wenger said: “Recently we’ve hit the wall a little bit.
“Not spectacularly but enough that we are not able to push on like on Wednesday night (against PSV).
“On Wednesday we looked for something special but it didn’t come because at the moment it is not in the team.
“It’s the first time it has happened and I’m a little bit lost at the moment.
“I’m always planning for the next game but at the moment it is a shock to the system as a club because it’s the first time, but I am very busy planning for the Premier League.”