Brighton and Gruda, 20, have reached a four-year agreement, and Hurzeler, the manager, is excited to work with the midfield player.
He made 28 appearances in his breakout season with Mainz last year, helping the team to stay in the top division.
“I saw the big impact he made last season in the Bundesliga and he’s a player I admire a lot,” stated Hurzeler.
Gruda had been strongly linked to a transfer to Bayern Munich. Prior to Euro 2024, he trained with Germany’s senior team and was expected to be called up before having to withdraw due to injury.
He represented Germany in every youth age group.