1. FC Union Berlin have completed the signing of central defender Nicolai Rapp from FC Erzgebirge Aue. The 22-year-old has signed a deal until the summer of 2022 at the Stadion An der Alten Försterei.

Rapp's football career began at FC Friya Limbach before he was introduced to the academy of TSG Hoffenheim. In 2014, Rapp won the U19 German Championship with Hoffenheim alongside current Union Berlin players Grischa Prömel and Joshua Mees. Rapp enjoyed an 18-month loan spell at Greuther Fürth and earned a permanent deal to Erzgebirge Aue, where he made 16 appearances this campaign.

"I'm happy that the change to Union Berlin has worked out and I'm looking forward to the new challenge. I have heard a lot of good things about the club and I'm looking forward to the challenging task in Berlin. For me personally, it is now a matter of establishing myself in the team as quickly as possible and contributing to the success of the team with my qualities," said the defender.

"In Nicolai Rapp, we were able to get a young, talented player who, despite his age, already has a lot of experience in the second division. We have observed his development for some time and are convinced that he can be a reinforcement for us in all defensive positions," said Oliver Ruhnert, the Managing Director for Professional Football at 1. FC Union Berlin.

The fee between Union and Aue will remain undisclosed and Rapp's contract at the club is valid for both Bundesliga and 2.Bundesliga football.