American midfielder Joe Gyau is moving from Hoffenheim to Borussia Dortmund II, the club's reserve team in Germany's third division.
The transfer was announced Monday on Dortmund's website.
The 21-year-old from Silver Spring, Maryland, is a member of the U.S. under-23 team that failed to qualify for the London Olympics. He made his debut for Hoffenheim's first team Feb. 8, 2012, in a German Cup quarterfinal loss to Greuther Fuerth. He appeared in the Bundesliga for the first time this spring as a second-half substitute against Eintracht Frankfurt on April 26 and Dortmund on May 3.
Gyau spent most of the 2012-13 season on loan to St. Pauli of the second division.
His father, Philip, made six appearances for the U.S. national team and his grandfather, Joseph, played for Ghana.