American forward Gio Reyna will miss several weeks with Borussia Dortmund after straining his left groin while training with the U.S national team.

Reyna was hurt last week in Kansas City, Kansas, and returned to Germany, missing a 2-1 loss to Canada and a 1-1 draw with New Zealand in a pair of friendlies.

Reyna is not training with Dortmund ahead of a game Friday against Heidenheim.

"That will unfortunately take a few weeks,” Dortmund coach Nuri Sahin said Wednesday of Reyna's return.

Reyna played just 280 league minutes for Dortmund in the first half of last season and 235 for Nottingham Forest following a Jan. 31 loan. He played just 10 minutes during Dortmund’s first two Bundesliga games this season.

Reyna, 21, is a son of former U.S. captain Claudio Reyna.