Germany midfielder Sami Khedira will miss Juventus' Champions League tie at Atletico Madrid on Wednesday after being diagnosed with an irregular heartbeat.
Juventus have revealed the 31-year-old will be sidelined indefinitely while he undergoes treatment for atrial arrhythmia.
The condition causes an irregular and often abnormally fast heart rate and can lead to issues including dizziness, shortness of breath and tiredness.
A statement from the club said: "Sami Khedira remained in Turin for medical examinations, from which emerged the opportunity to perform an electrophysiological study and eventual treatment of an atrial arrhythmia which appeared today."
Khedira, who missed Germany's World Cup final win over Argentina in 2014 after being hurt in the pre-match warm-up, has made only 15 appearances this season because of injury.