Borussia Dortmund on Thursday completed the signing of young German defender Matthias Ginter from Frieburg. The 20-year-old signed a five-year contract after returning from the World Cup inBrazil, where he was part of Germany’s winning team. Ginter, a center back, will rival Mats Hummels and Sokratis Papastathopoulos for a spot in the BVB’s back four, whileNeven Subotic is also expected back from injury soon to provide further competition.