The 24-year-old, who has previously had loan spells with Holstein Kiel and Jahn Regensburg in the 2. Bundesliga, has signed a two-year contract with die Lilien.
Kicker report he has moved for nothing but Mainz have a sell-on clause so could still benefit financially from him in the future.
Due in part to fitness, he made just nine appearances, and just one start, for Regensburg in his spell there in the second half of last season, but until a heel injury in his second season he made a stronger impression with Kiel, scoring four goals and creating five in 35 appearances.
The former Germany under-21 international also made six appearances in the Bundesliga for Mainz, scoring one goal. He now makes the short trip to Darmstadt, with is just south of Langen, where the native Hessian was born.
“I have always followed the Lilies with one eye and perceived them as a very friendly club with great fans,” he says about his new club, adding he is “delighted” to be able to play for them and be reunited with Markus Anfang, his coach in his first season at Kiel.
Director of Sport Carsten Wehlmann, another ex-Kieler, says that the tall Seydel can be used across the front line and “he has already gained a lot of experience… and proven his qualities,” in the second tier. “We are pleased that he would now like to take the next step in Darmstadt,” he concludes.
He is the club’s second signing of the summer, following Lars Lukas Mai. He is not intended as a replacement for Serdar Dursun, whose future at the club remains in doubt with numerous clubs, including Hannover, interested in the striker.
Header image source: SV Darmstadt 98.