The confidence levels in Arsenal's defence at present must be pretty low after that defeat against Aston Villa, a game of which saw Gabriel Agbonlahor surge through their back-line with far, far too much ease at one point. However, the good news is Bacary Sagna should be fit despite sustaining a knock against Villa at the weekend. His colleague Kieran Gibbs is also in contention and could play alongside the Frenchman with Per Mertesacker likely to start at centre-back. There's an issue as to who could join him at the heart of defence though as Thomas Vermaelen is out until the middle of September with a back-injury. Laurent Koscielny is likely to fill in as his suspension does not carry forward into European ties, though there are doubts over the France international following his reckless red card at the weekend. Sagna, Mertesacker, Koscielny, Gibbs