Andre Hahn has completed a move back to Hamburg, leaving Borussia Monchengladbach after three years at the Bundesliga club.
Former Hamburg youth player Hahn has signed a four-year deal at his old club, having scored 19 goals in 95 games for Gladbach.
The 26-year-old only hit three Bundesliga goals last season after falling out of favour, starting 18 matches in the league as Gladbach finished ninth in the table.
"I had a nice time at Borussia and will always have memories upon which I can fondly look back on," said Hahn.
"However, the time has now come for me to take on a new challenge. I know Hamburg well and I'm really looking forward to what lies ahead."
Hahn has a single cap for Germany, with his only international appearance to date coming against Poland in a May 2014 friendly played at Hamburg's Volksparkstadion.
Hamburg's preparations for the new Bundesliga season have included snapping up Greek defender Kyriakos Papadopoulos, signing United States international striker Bobby Wood to a new contract and allowing goalkeeper Rene Adler to join Mainz.