If there has been anything that has slowed the Gunners down more than anything else, it is injuries.
The lack of health with their players is startling and highly disruptive to maintaining a batch of players who is playing together week in and week out.
Not only does it mess up team-building, but it's usually someone crucial to their play at the time, getting injured by a wild, flying challenge by someone else (see: Ramsey's leg break, Sagna's leg break, Eduardo's ankle break).
Now, this can all be put down to the chances of the play. Harsh challenges coming in is merely another part of the game. But, these hamstring, calf, groin, and even abdominal muscle pulls are a bit silly.
I know, as a player who has played the game for 14 years, that you know when you have a tight muscle or aren't able to stretch out to the necessary extent that you need to play.
Sure, they have a few that were a bit unfortunate, especially the hamstring pulls, because those feel like you were shot in the back of the leg, but a player at the professional ranks should know the physical limits of their body.
Yes, go in hard for challenges—never give that up—but don't put the team at risk of losing a key asset to their success by going in for an unnecessary challenge and overextending yourself.
A bit much to ask of a player at the peak of their play, but in order for Arsenal to reach their peak again, there needs to be more mindfulness of this risk.