4. Mats Hummels
Sticking with defence for a moment, it is quite common knowledge that Arsenal need a new, world class centre back and have in fact been screaming out for one for years. Not since the days of Sol Campbell and Kolo Touré has the heart of the Gunner's back four looked sturdy and this is clearly an issue that needs addressing. Per Mertesacker runs hot and cold and has been in and out of the team this season, and could join Thomas Vermaelen
in being sold this summer if the latest rumours are accurate. Sebastien Squillaci must also surely be cast onto the scrapheap now the season is over as Wenger looks to bring in some much needed steel. According to reports, the Frenchman
wants to bring in Mats Hummels to fill at least one of the centre back spaces that will surely be freed up within the next few months, and the Borussia Dortmund man ticks all the right boxes. Arsenal like to buy in young players who they can then develop and the 24-year old German international matches that criteria. He's also defensively solid and reliable - he has started all of Dortmund's games this season and helped them to the final of this season's Champions League and goodness knows Arsenal need a defender with these credentials.
Cost: £17.6 million