Bild reports that Bundesliga club Mainz is interested in Fabio Gruber, the 23-year-old captain of 1. FC Nürnberg and a Peruvian international centre-back. Other Bundesliga teams, specifically Augsburg and Gladbach, have also shown interest in the player. Gruber, who holds both Peruvian and German citizenship, has three caps for Peru. He joined Nürnberg in February 2025 from Verl for a reported €700,000. His current market value is €2.00m, according to Transfermarkt.