"We are pleased to announce the transfer of Mladen Petric to Hamburg, and we wish Mohamed Zidan the best with Dortmund," a statement on Hamburg's official site read.

Hamburg paid €4.5M in addition to the services of Zidan, who failed to impress at Nordbank Arena since joining last season.

The Egyptian striker reunites with former Mainz boss Jurgen Klopp, who is considered a 'Godfather' for the 26-year-old.

"It’s a pity that I had to leave Hamburg so quickly, but I am sure I have made the right decision to join Dortmund," Zidan said in an interview with HSV.de.