On 2 December 2017, the Greek international renewed his contract with the Giallorossi, until 2022, with a release clause set at €35 million. On 15 October 2017, the Greek defender was substituted during the Serie A match against Napoli that took place at the Stadio Olimpico in Rome. The Greek defender was out for almost a month due to a Grade I strain of his left adductor longus (thigh) muscle. On 31 October 2017, he returned to the squad in a convincing 3–0 Champions League home game against English champions Chelsea F.C. On 5 November 2017, he scored his first goal in 2017-18 season from an Edin Džeko assist in a 4–2 away win against Fiorentina.