Kammala jumla mai zuwa: Cahill ya fara wasan farko a wasan farko na José Mourinho a matsayin mai horar da Chelsea, yana taimaka musu su ci gaba da samun nasara a wasan da suka yi nasara da Hull City a ranar 18 ga watan Agusta 2013. Kwana goma sha biyu bayan haka, Cahill ya karbi katin rawaya na farko a kakar wasa ta bana yayin da Chelsea ta fadi a Bayern Munich a bugun daga bayan da kungiyoyin suka buga wasa 2-2 a gasar cin kofin duniya.
2013 UEFA Super Cup, wanda aka gudanar a Eden Arena a Prague.