2019, on the last matchday of the season, Mavropanos was partnered with Shkodran Mustafi at centre-back, but was replaced by Laurent Koscielny after half an hour due to injury in a 3–1 away win against Burnley. Loan to 1. FC Nürnberg On 13 January 2020, after struggling for match time at Arsenal, Mavropanos moved to 2. Bundesliga club 1. FC Nürnberg on loan for the remainder of the 2019–20 season, and the Greek international picked up momentum in the heart of the Nuremberg defence with three stellar performances in a row. He won consecutive Man of the Match awards in his second and third game for the club, before making a key goalline clearance in his fourth. On 25 February 2020, Mavropanos picked up an injury playing against Darmstadt 98; the club was unsure of how long he would be absent. Loan and permanent move to VfB Stuttgart On 16 July 2020, Mavropanos signed a new deal with Arsenal and joined VfB Stuttgart on a €250.000 loan for the 2020–21 season. At Stuttgart he was reunited with Sven Mislintat who had originally scouted and signed the player for Arsenal. On 3 October 2020, Mavropanos made his competitive debut for Stuttgart in the Bundesliga against Bayer Leverkusen; the game ended in a 1–1 draw. On 15 October 2020, Mavropanos suffered an injury during a friendly with SC Freiburg and underwent an operation on his meniscus. On 24 June 2021, his loan deal was extended for a second season, with an option to make the loan permanent with a purchase option of €3.5 million at the end of the season. On 7 August 2021, a week before hosting Greuther Fürth for the Bundesliga premiere, Mavropanos scored a header from a corner kick against BFC Dynamo as he started the first round of the DFB-Pokal. On 28 August 2021, Mavropanos scored his first Bundesliga goal as he battled his way through three defenders before exchanging passes with Hamadi Al Ghaddioui and sent a fine finish into the top corner in a home Bundesliga game against SC Freiburg. On 2 October 2021, with an hour played, Konstantinos Mavropanos collected the ball on the right, burst through the Hoffenheim defence, and unleashed a fierce left-footed drive to double Stuttgart's advantage in a 3–1 home Bundesliga win. On 16 October 2021, the Greek central defender opened the scoring in the 15th minute with a shot from