This file photo taken on November 28, 2015 shows Bayern Munich's Spanish midfielder Javi Martinez during the German first division Bundesliga football match FC Bayern Munich vs Hertha Berlin in Munich, southern Germany. Javi Martinez underwent a knee operation on February 3, 2016 (AFP)
Bayern Munich defender Javi Martinez, out for four weeks with meniscus damage, said the injury was "not too serious" with his knee surgery having gone well.
The Spain international underwent surgery in Barcelona on Tuesday, joining fellow central defender Jerorme Boateng, out for three months, on the sidelines at Bayern.
"Thank you all for caring. Fortunately it is not a serious injury," Martinez said on Twitter.
Bayern, chasing a treble of titles in coach Pep Guardiola's last season at the club, are struggling with their central defenders, with Medhi Benatia also out and still working on his comeback from injury.
The German champions signed central defender Serdar Tasci on loan from Spartak Moscow on Monday in an effort to plug the gaps left by the injured players.
Bayern are top of the Bundesliga with an eight-point lead and are also in the running for the Champions League, where they face Juventus in the round of 16 later this month, and the German Cup.
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