Juventus midfielder Sami Khedira has been ruled out for a month with a heart problem.
The 31-year-old has atrial arrhythmia, a heart condition which causes an irregular and abnormally fast heart rate.
The conditions can lead to shortness of breath, dizziness and tiredness.
Khedira is expected to miss both of Juventus’ Champions League last-16 legs against Atletico Madrid.
Injuries have restricted the Germany international to just 15 appearances this season.
A Juventus statement said: “After a short period of convalescence, he will be able to resume his activity approximately within one month.”
Juventus, who have reached two of the last four Champions League finals, are 13 points clear at the top of Serie A.