Monreal has got LCB covered for another season or two at least. He's had few injury problems as far as I know, and only seems to be getting better with age. However he's not a traditional CB in a back 2, Wenger needs to remember that. Ideally we'd sign Gimenez or De Vrij for free, loan out Holding, keep Chambers as a backup. Kos is great but he only has another 1-2 seasons in him, and can't be relied upon for playing more than one game per week. Holding needs a loan to get some first team experience.