Bayern Munich central defender Medhi Benatia could miss both legs of their Champions League quarter-final against Porto due to a muscle injury.
The 27-year-old was taken off in the first half of their victory on penalties over Bayer Leverkusen in the German Cup last eight on Wednesday.
The Morocco international said on his Twitter account that a medical examination suggested he would be out for between "two and four weeks".
"Disappointed but it's an occupational hazard," he added.
The was no official comment on the injury from Bayern, who travel to Porto next week before the return leg in Munich later this month.
Benatia joins a long injury list at Bayern that includes Bastian Schweinsteiger, David Alaba, Javi Martinez and reserve keeper Tom Starke.
Franck Ribery, who has been out for weeks with an ankle injury, returned to training on Wednesday while Thiago Alcantara has only just returned to action after a year out injured.
Bayern, 10 points clear at the top of the Bundesliga, are still in the hunt for three titles.
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