Holtmann leaves Mainz after four years, having made just 29 appearances for the Bundesliga club.
He did though have a loan spell with Paderborn last season, scoring one goal in 24 matches for the relegated side. He also previously played with Braunschweig. He has signed a three-year contract with Bochum
Sporting director Sebastian Schindzielorz says the 25-year-old is “a very dynamic attacker, with a high speed and a strong left foot,” and that he “will enrich our offensive game with his pace.”
Elsewhere, St. Pauli have signed Nigerian defensive midfielder Afeez Aremu from Norweigian side IK Start.
The ‘dynamic clearer,’ as coach Timo Schultz calls him, made 63 appearances for his former side, contributing five goals, and played in both the first and second tiers of Norweigian football.
Braunschweig meanwhile have signed striker Njegos Kupusovic from Red Star Belgrade, handing him a three-year contract.
The 19-year-old was on loan at Erzgebirge Aue last season, arriving when now-Braunschweig coach Daniel Meier was in charge, but only made three appearances at the back end of the season, scoring in the defeat to Bochum.
Another Aue player, Paul Horschig, has also left today to join Regionalliga side VfB Auerbach, where he spent last season on loan. Tobias Fleckstein has left Holstein Kiel to join MSV Duisburg. In addition, former Karlsruher SC man Burak Camoglu has joined Turkish side Hatayspor.
Header image source: VfL Bochum.