#2 James Tarkowski
As good as Arsenal has been going forward, they have been just as leaky in defence. Shkodran Mustafi is just not cut out for it, while Sokratis can't fend off attacks all by himself. The perfect partner for him would be Burnley defensive general, James Tarkowski.
This season in the league alone he has averaged 3.2 tackles and interceptions along with an astronomical 6.6 clearances per match. This might be down to the fact that Burney sits deep and defends in numbers. Going forward, he is pretty good as well. He makes around 34 passes per game along with 3.3 accurate long balls per match. This shows that although he doesn't have the ball for long spells of the game, he knows what to do when he does have the ball at his feet. He has also chipped in with 3 goals and an assist again showing that in a better team he does have the underlying numbers to be the best.
A tall, strong, ball-playing defender who is good in the air as well is what Arsenal need to fully immerse themselves in Emery's free-flowing, expansive football. Valued at £15 million he would be an astute signing that will solve a lot of issues as well as allowing the club to invest elsewhere in the squad. In addition, at 26 years of age, he could form a good partnership with Rob Holding when the latter returns from his long-term knee injury next season.