Bayern Munich's Spanish international Javi Martinez was ruled out until 2015 on Thursday after rupturing knee ligaments in the German SuperCup defeat to Borussia Dortmund, the champions announced.
"Javi Martinez will be unavailable until the end of 2014," said Bayern on their official website, while Spanish media estimated that the absence would be between six and seven months.
The 25-year-old defender or midfielder, who moved to Bayern in 2012 for 40 million euros ($53 million) from Athletic Bilbao, required lengthy medical treatment after landing awkwardly following a tackle by Dortmund defender Marcel Schmelzer on the half-hour mark of Wednesday's match.
He was replaced by Brazilian defender Dante.
Dortmund went on to win the SuperCup for the second successive year, beating Bayern 2-0.