According to Bild, a possible transfer of Marvin Friedrich to Mainz, the club of his former coach Urs Fischer, appears to have been unsuccessful.

According to Kicker, FSV Mainz 05 is interested in 30-year-old German defender Marvin Friedrich as a defensive reinforcement. FSV Mainz 05, which is seeking to strengthen its central defense, has identified Marvin Friedrich as a potential immediate reinforcement. The defender had a successful working relationship with the current Mainz coach, Urs Fischer, during their time at Union Berlin. Friedrich is currently considered likely to leave Borussia Mönchengladbach, having recently failed to make the matchday squad. A loan is not possible because his contract expires in the summer. It has been suggested that to address the potential for the player to be hesitant about joining a club threatened by relegation, Mainz could offer a contract for the 2026/27 season that is only valid for the top division, which would allow him to leave on a free transfer if the club is relegated. Friedrich joined Gladbach on 11/01/2022 and has made 4 Bundesliga appearances this season. According to Transfermarkt, he has a current market value of €1.80m. He has also been capped 4 times for Germany's U20 team.