Borussia Dortmund midfielder Nuri Sahin will miss the rest of the season because of a knee injury with his team set to win the Bundesliga title.

Dortmund says Sahin partially tore ligaments in his right knee in Sunday's 3-0 win over Freiburg and will be out for at least six weeks.

After Bayer Leverkusen lost 5-1 at Bayern Munich, Dortmund opened up an eight-point lead in the standings with four rounds left.