All eyes turn to our central defenders as other alternatives. Johan Djourou has been given the nod at right back this season when our current first choice duo have been out but that was before Thomas Vermaelen was fit and ready for action. With the extra experience given by Mertesacker in central defence, Wenger could move Koscielny as the more positionally defensive full back, giving Santos a licence to get forward and support the attack a little more from the left. I suppose this all depends