Gibbs out of Besiktas clash

Arsenal will be without defender Kieran Gibbs (hamstring) for Tuesday night’s Champions League play-off first leg against Besiktas in Istanbul.
Centre-back Laurent Koscielny has shrugged off an Achilles problem and midfielder Mathieu Flamini returns after missing the Barclays Premier League win over Crystal Palace, but forward Yaya Sanogo (hamstring) did not travel.