On 7 January 2014, Nainggolan was loaned to fellow league team Roma until the end of the campaign for a fee of €3 million, with an option to purchase 50% of his rights in the ensuing summer for €6 million. He made his debut two days later, starting in a 1–0 home win over Sampdoria for the Coppa Italia which qualified to the quarter-finals. In the same competition, he also helped dispose of Juventus in said stage by playing the full 90 minutes 12 days later.