Javi Martinez will miss the first leg of Bayern Munich's clash with Juventus in the Champions League round of 16 after undergoing knee surgery on Tuesday.
The Spaniard has been ruled out for four weeks following the operation, meaning he will be sidelined when the Bundesliga leaders travel to Turin on February 23.
Prior to Bayern's announcement Martinez insisted on Twitter the injury was not serious, but the 27-year-old has a history of fitness problems.
Martinez spent nearly a year out after a cruciate knee ligament rupture in August 2014, only returning to full fitness in September 2015.
He has made 18 appearances in all competitions this season and adds to Bayern's defensive concerns following an abductor injury to Jerome Boateng.
Coach Pep Guardiola does have further options at the back, though, after the loan signing of Serdar Tasci from Spartak Moscow on Monday.