Schalk Burger is in hospital with bacterial meningitis and will only play rugby again in June.
Fiona de Souza, a spokeswomen for the Burger family, said in a statement that if everything went well with the recovery the Bok flanker would be in hospital for the next 14 days and then it would be at least another six weeks before he would be fit to play rugby.
Burger contracted the potentially serious infection after surgery on a calf muscle to reduce pressure on a nerve.
Burger has not played rugby since tearing knee ligaments 15 minutes into the 2012 Super Rugby season.
Bacterial meningitis is an inflammation of the protective membranes that cover the brain and spinal cord.
Burger was part of the 2007 World Cup winning Springbok squad and is a past winner of the IRB World Player of the Year award.