Front row blow for Pumas
The 26-year-old front row forward has ruptured medial ligaments in his knee and have undergone surgery.
Team doctor Guillermo Botto said Herrera will require between about four to six weeks to recover, playing him in doubt for the World Cup – which gets underway on September 18.
He has been replaced in the 26-man squad – for the Rugby Championship Test against South Africa in Durban on Saturday – by veteran prop Juan Pablo Orlandi, who last played for Los Pumas against England in November 2013 against England.
The 32-year-old Orlandi played in 15 Tests for his country before being axed. He has now been thrown a World Cup lifeline.
Pumas coach Daniel Hourcade said they will continue to "evaluate" players ahead of next month's World Cup – when they face the Boks in Durban this week and Buenos Aires a week later.
"The goals for the matches against South Africa are the same as for the previous ones, to gradually improve our game," Hourcade said.
"It's an important game.
"We will seek to further improve our game and find the rhythm that we lacked [in defeats against Australia and New Zealand]."
He said South Africa is an "extremely strong" team, which plays with the same tempo as the All Blacks and Wallabies.
However, he felt the Boks base their game primarily on contact.
"It will be important that our defence is on par, something that we failed to achieve in our previous outings.
"South Africa is a great team could have won the two games they played," he said of the 20-27 loss to New Zealand and 20-24 loss to Australia, both defeats the result of late scores by the opposition.
Hourcade said their focus remain the Rugby Championship, but said they also needed to "rotate" players ahead of the World Cup.
Argentina squad: Horacio Agulla, Matías Alemanno, Marcos Ayerza, Marcelo Bosch, Agustín Creevy, Tomás Cubelli, Jerónimo De la Fuente, Matías Díaz, Lucas González Amorosino, Santiago González Iglesias, Juan Martín Hernández, Juan Imhoff, Martín Landajo, Tomás Lavanini, Juan Manuel Leguizamón, Tomás Lezana, Benjamín Macome, Pablo Matera, Julián Montoya, Lucas Noguera, Juan Pablo Orlandi, Guido Petti Pagadizabal, Leonardo Senatore, Juan Pablo Socino, Nahuel Tetaz Chaparro, Joaquín Tuculet.
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