Hamburg have completed the signing of Nicolai Muller from fellow Bundesliga side Mainz.
It is believed that the 26-year-old winger, who has agreed a four-year contract at the Imtech Arena, has cost the Dinosaurs £3m.
"Nicolai is a player who improved constantly over recent years and is always able to reach an even higher level," said Hamburg's chief executive Dietmar Beiersdorfer.
"That is in keeping with Hamburg and the aims we have to improve step by step. His versatility is going to be particularly helpful to our attack while his pace and strong shot will also help. Furthermore, Nicolai has always kept his feet on the ground, despite the success he has had."
Muller has made two appearances for Germany at senior international level.