The end of the season will signal many changes, and a whole host of our players will be fighting for their futures.Some may already have their cards marked, but there will be more than a few who will need every game from now until the last game of the campaign to impress themselves on Unai Emery’s future plans.It won’t simply be displays that Emery will be keen to watch. There are other variables such as injury record that will go a long way to deciding whether the exit door at Colney will be open for business.Another that may call the end of some Gunners’ careers will be age - and this may well be the sole reason why our defence is in serious need of replacements.Laurent Koscielny - 33Nacho Monreal - 33Sokratis will be 31 by the end of the season.That is three integral members of our defence that have their best years behind them. Three defenders who comprise the better part of our backline that may well be on the way out.That’s not to mention 35 year old Stephane Lichtsteiner.So, best case scenario would be that these players stay fit and healthy and their levels don’t dip.Worst case scenario?We need to replace these stalwarts with new blood. New blood we can scarcely afford.There is a middle ground too.We are missing virtually a whole defence with long term injuries and loans right now. We have replacements that can stand in when the wear and tear of age saps the muscles of our veterans - and we will have the veterans to teach the lessons to our younger players.Step forward Rob Holding, Hector Bellerin and Calum Chambers.The jury may well still be out in regards to Chambers, but most would agree he deserved a shout at the first team before he was surprisingly loaned to Fulham. He has the talent - he has shown it in the sporadic appearances he has made for us, we just need to decide if he can maintain a level of consistency.Rob Holding has impressed Emery and was very much in the eleven when he suffered his long term ailment. He will return stronger for it.Then we have Bellerin, who was showing the form of his life before his ACL twanged like an elastic band.Combine these three with Ainsley Maitland-Niles and the experienced three mentioned earlier, and we have the semblance of a blended defence.There can be no doubt we still need to recruit more numbers, but perhaps the catastrophe isn’t quite so catastrophic as we had assumed it would be.The time to recruit heavily in our defence is coming, but it isn’t quite Black Friday yet. Our veterans demand our respect after years of putting it all on the line in every game. They deserve to be able to go into what will most likely be their last seasons with their head held high.Let us see what they’ve got left in the tank.