Cahill made his season debut in José Mourinho's first match back as Chelsea manager, helping them keep a clean sheet in a 2–0 victory over newly promoted Hull City on 18 August 2013. Twelve days later, Cahill picked up his first yellow card of the season as Chelsea fell to Bayern Munich on penalty kicks after the teams played out a 2–2 draw in the 2013 UEFA Super Cup, held at the Eden Arena in Prague.