Prop Matias Diaz has been ruled out of Argentina's Rugby World Cup campaign after suffering heart palpitations.
The 22-year-old tight-head reported to Pumas training on Wednesday but will be replaced in coach Daniel Hourcade's 31-man squad by Juan Pablo Orlandi.
Diaz had undergone cardiological checkups in June, which were normal, while new tests proved inconclusive.
The former Highlanders front-row will continue to be monitored and has been advised a two-month period of rest, hence ruling him out of the World Cup.
Hourcade said: "[This] is taken for damage and is something that can always happen and so we have a list of reserves in each position."