#2 Mesut Ozil's absence
Not only did the gruelling two-legged UEFA Europa League semi-final against Atletico Madrid knock Arsenal out of the tournament, but it also seems to have taken a deeper toll on the Gunners.
Midfield talisman Mesut Ozil has reportedly been struggling with a bad back in recent weeks and as a result has missed out on Arsenal's last 6 Premier League games. While he may have been called upon for the duel against Atletico, it did prove to be futile towards the end, and may have also hampered Ozil's recovery process.
With the World Cup looming, Ozil was given a rest yet again last night and his absence certainly reflected on the team. The German's creativity was visibly lacking as Arsenal's did fight tooth and nail, but just weren't good enough to find a breakthrough until the second half.
In Ozil's absence, the midfield trio of Alex Iwobi, Granit Xhaka and Aaron Ramsey only managed to complete a combined total of 4 key passes. Stats like these just make you wonder how different things could've been had Ozil been at the fulcrum of the attack.