Amankwaah made his 100th career appearance for Sutton on 3 December 2016 in a 2–1 win against League Two club Cheltenham Town in the FA Cup 2nd round. He went on to appear in every round of Sutton's historic run to the 5th round of the FA Cup for the first time ever, including appearances in a 3–1 victory over local rivals AFC Wimbledon of League One on 17 January 2017, a 1–0 victory over Championship side Leeds United on 29 January and an eventual 0–2 defeat to Premier League club Arsenal on 20 February.