Chelsea's Brazilian-born Spanish striker Diego Costa (2nd L) celebrates with Brazilian midfielder Willian (3rd L) after Costa scored his team's first goal during the English Premier League football match between Chelsea and Aston Villa at Stamford Bridge in London on October 17, 2015. AFP PHOTO / OLLY GREENWOOD 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 75 images, no video emulation. No use in betting, games or single club/league/player publications.