Borussia Dortmund will be without Paraguay striker Lucas Barrios for up to six weeks as it begins the defense of its Bundesliga title.

The club first expected Barrios to be out for two to three weeks after he injured his thigh injury in the Copa America final, but new tests upon the player's return to Dortmund revealed a more serious injury.

Dortmund coach Juergen Klopp says he is angry at the Paraguayan federation for giving the club wrong information about Barrios' injury.

Dortmund kicks off the season against Hamburger SV on Friday.