Arsenal are very good at throwing away their Premier League title chance every time they have a chance these days. You would remember what happened in the recent years while they were 1 vs 1 with Manchester City. 

I'm sad for them. Arteta has built a really solid team in time. There are very capable young players in the squad. Honestly I see the thing they lack for a trophy here as a reliable CF. They don't have it for a long time. Gabriel Jesus recovered from a lasting injury first and made a really good comeback too. But in a very short time, he got another serious injury and he isn't expected to return before August... Arteta is also aware of this problem but they still haven't signed anyone. If they want the title then they have no choice other than doing this.