Arsenal's French defender Laurent Koscielny (bottom) tackles Chelsea's Brazilian-born Spanish striker Diego Costa (top) during the English Premier League football match between Arsenal and Chelsea at The Emirates stadium in London, on September 24, 2016. / AFP / IKIMAGES / Ian Kington / RESTRICTED TO EDITORIAL USE. No use with unauthorized audio, video, data, fixture lists, club/league logos or 'live' services. Online in-match use limited to 45 images, no video emulation. No use in betting, games or single club/league/player publications. (Photo credit should read IAN KINGTON/AFP/Getty Images)
