On 22 January 2014, Ki reached his second consecutive League Cup final as he helped Sunderland defeat Manchester United 2–1 on penalty kicks after the two-legged semi-final had finished level on aggregate, with Ki and Marcos Alonso scoring Sunderland's penalties. Ki played against Manchester City in the League Cup final on 2 March, but despite leading 1–0 at half-time, they were overpowered by City in the second half, eventually losing 3–1.