Toulouse goalkeeper Yohann Pele has been diagnosed with a blockage in his lung and will be unavailable for a minimum of six months.
The 27-year-old has suffered a bilateral pulmonary embolism and was hospitalised on Tuesday morning.
Pele will now face a rehabilitation period that lasts until at least April, meaning he is likely to miss the remainder of the season.
A statement on the club's official website said: "Toulouse goalkeeper Yohann Pele has suffered a bilateral pulmonary embolism. His unavailability is a minimum of six months.
"All at TFC wish the player a speedy recovery a lot of courage."
Pele has been plagued by injury and health problems since joining Toulouse from Le Mans before the start of last season.
He suffered a hand injury and a ruptured posterior ligament, before suffering from phlebitis, a vein inflammation which can lead to a pulmonary embolism, in the summer.