ST ALBANS, ENGLAND - JANUARY 12: (L-R) Per Mertesacker and Calum Chambers of Arsenal during a training session at London Colney on January 12, 2016 in St Albans, England. (Photo by Stuart MacFarlane/Arsenal FC via Getty Images)
ST ALBANS, ENGLAND - JANUARY 12: (L-R) Per Mertesacker and Calum Chambers of Arsenal during a training session at London Colney on January 12, 2016 in St Albans, England. (Photo by Stuart MacFarlane/Arsenal FC via Getty Images)