South Africa lock Eben Etzebeth faces up to five months on the sidelines after being told he needs surgery on a foot injury.
Etzebeth sustained the injury during last weekend's win over France in Paris and will have an operation in Cape Town on Monday.
The 22-year-old was recently named as one of the five nominees for the International Rugby Board World Player of the Year Award for 2013.
"At this point in time, the specialist's assessment is that Etzebeth will be out of action for a minimum of 16 to 18 weeks," said a statement from the Stormers, his Super Rugby team.
Etzebeth also missed the start of last season after injuring an ankle in a pre-season match.
The Stormers recently signed Argentinian lock Manuel Carizza, who arrives in Cape Town in January.