The 25-year-old defensive midfielder, who moved to Bayern in 2012 for 40 million euros ($53 million) after impressing at Athletic Bilbao, required lengthy medical treatment after landing awkwardly following a tackle by Dortmund defender Marcel Schmelzer on the half-hour mark.

He was replaced by Brazilian defender Dante.

According to German media reports the injury is to his cruciate ligaments and Bayern Munich's sporting director Matthias Sammer admitted to German broadcaster ZDF it didn't look good.

Dortmund went on to win the SuperCup for the second successive year, beating Bayern 2-0.