Argentina captain Agustin Pichot will miss tonight's second Pool D match against Georgia because of a muscle strain in his right leg.
Pichot will be replaced at scrumhalf by Nicolas Fernandez Miranda. Utility back Hernan Senillosa comes on to the bench.
Team doctor Mario Larrain said Pichot needed four to five more days to recover and would be fit for the following game against Namibia on September 22nd.
Pichot played a key role in Argentina's 17-12 upset win over hosts France in Friday's opening match. His role as captain is likely to be taken over by centre and Leinster clubman Felipe Contepomi.