Rebuild: Three Arsenal weak links and three perfect signings if Gunners are to move forwards

Upgrade – Mats Hummels (Borussia Dortmund)

Hummels is rated as amongst the finest central defenders in Europe and, considering Borussia’s nightmare start to the Bundesliga season, he could well be available in January at the right price – signing Hummels would seal a solid partnership between him and Laurent Koscielny for the next few years at least.