to their acquisition of defender Dayot Upamecano from Salzburg during the winter transfer window, Papadopoulos moved to Hamburger SV. The HSV manager Markus Gisdol knew the defender from their time together at Schalke 04. On 21 January 2017, he made his debut with the club as a starter in a 1–0 away loss to VfL Wolfsburg. On 3 February 2017 Papadopoulos scored a headed goal from a set piece against Bayer Leverkusen, giving Hamburg a 1–0 victory over his parent club. A week later, HSV celebrated back-to-back Bundesliga wins for the sole second time this season as Papadopoulos scored against his last club in a 3–0 away win at RB Leipzig. On 18 February 2017, in his fourth Bundesliga game with Hamburg, he was substituted in the first half due to a shoulder injury. On 1 March 2017, Papadopoulos returned in the DFB Cup against Borussia Mönchengladbach. On 18 March 2017, in a 0–0 away draw against Eintracht Frankfurt, he reached 100 appearances in the Bundesliga wearing the jersey of four clubs. On 21 June 2017, having narrowly avoided relegation the previous season, Hamburger SV signed Papadopoulos on a permanent three-year deal from Bayer Leverkusen on a €6.5 million transfer fee, with the Dinosaurs to offer another €3 million in the form of a target bonus, for the next three years. On 9 August 2017, despite having been with the club for only six months, he was named vice-captain for the 2017–18 season. On 12 December 2017, he scored his first goal for the season in a 2–1 home loss against Eintracht Frankfurt. On 23 July 2018, according to the Hamburger Morgenpost, Papadopoulos was suffering from a knee cartilage injury which required immediate surgical treatment. The rehabilitation period was estimated at six months, meaning he would will be able to compete again around Christmas, missing at least the first half of the 2018–19 2. Bundesliga season. On 30 March 2019, he returned to the squad as a substitute in the bench, in an away 0–0 game against VfL Bochum after a difficult recovery process (154 days to be exact) from his cartilage damage and three days later he made his debut with the first team as a starter in a 2–0 away win DFB Pokal game against Paderborn. Lokomotiva On 27 October 2020, the Croatian football club based in Zagreb NK Lokomotiva officially announced the signing of Greek international for