#1 Lack of confidence
For a period of time, Arsenal were keeping clean sheets in games against Manchester United, Newcastle, Southampton and Watford. Petr Cech also worked hard to keep clean sheets in the Europa League. Now, the club's defensive woes have returned to haunt them. An embarrassing mistake from Shkodran Mustafi led to Arsenal's loss against Crystal Palace. From then, the team has lost confidence.
In the match against Leicester City, Ainsley Maitland-Niles' sending-off also dampened the spirit of the players. None of the players played with confidence. All of them were lacklustre in their passing, unlike their energetic selves when Arsenal faced Napoli.
Should Arsenal continue with this lack of confidence in their game, defeat is the only result that will emerge from the game for the Gunners. Emery will have to think of a way to inject some positivity into the team and rebuild the players' confidence following three consecutive defeats.