Phil Jagielka has admitted he is struggling to understand why Everton's defence is looking so shaky this season.
The Blues have already shipped 18 goals from eight games in the league this term following Saturday's 3-1 defeat at Arsenal.
David Moyes' side only conceded 33 in total last season and Jagielka admits he doesn't know why there has been such a dramatic change at the back so far.
The former Sheffield United man said: "It's hard to put a finger on why. We'd kept them quiet in the first half but then shot ourselves in the foot by not clearing the ball properly.
"At half-time we were looking OK but we've heard that one before already this season. The first half went to plan, and the second half didn't.
"We would prefer to be putting two good consecutive halves together in each game, but at the moment it doesn't seem to be working like that."