Arsenal came into Wednesday's Champions League match against Dinamo Zagreb expected to win easily, even if the match was in Croatia. Instead, they looked awful slumping to a shocking 2-1 loss. How the heck did that happen?
You can blame luck -- see Alex Oxlade-Chamberlain's own goal and a fortunate bounce to help Dinamo's second goal -- or you can blame Olivier Giroud for picking up two yellow cards in the first half. Those are both totally valid reasons, as it's hard to overcome a run of poor fortune when you're down a man. But if you want more technical reasons, there are two to offer up: poor midfield play, and horrifying set piece defense.
Central midfield has been a problem area for Arsenal for awhile now, using various patchwork pairings as injuries, poor form, and iffy fits personnel wise have left them with consistently shaky play in the middle of the pitch. That was on display in a big way in this match, as Santi Cazorla made consistently poor decisions in the pivot, while his partner, Mikel Arteta, had the following defensive contributions:
Mikel Arteta's tackle map tonight. Yep. pic.twitter.com/cwuRB2eTma— Squawka Football (@Squawka) September 16, 2015
That's not really what you want to see, especially in a Champions League match.
Add those midfield struggles to set piece defense that may as well not have been there, and you've got a recipe for disaster. Laurent Koscielny especially was a culprit on set pieces, doing an incredibly poor job of marking his man for Zagreb's second goal, and looked shaky at best on several other set pieces that Dinamo threatened from. It's been a consistent weakness of Arsenal's for a long time now, and until the Gunners figure out how to defend in dead ball situations, they're never going to be the truly elite team they want to be.
Fortunately, these problems are theoretically fixable, though Arsene Wenger and company are going to have to put in a ton of work to do it. They'll also probably have to dip into the transfer market to help their midfield, so they'll have to wait for January to make a meaningful improvement in midfield. They should be able to get through their Champions League group just fine with their current squad, but they'll need to play much, much better than they did Wednesday to assure that.