Pérez shuffles pack for Lions
Props Lucas Noguera and Ramiro Herrera come into the starting side for Santiago Garcia Botta and Nahuel Tetaz Chaparro, while in the second row Guido Petti comes in for Matias Alemanno
Jaguares also have an entirely new back row with Pablo Matera, Javier Ortega Desio and Leonardo Senatore replacing the trio of Facundo Isa, Juan Manuel Leguizamon and Tomás Lezana.
There is only one change in the backline from the 14-29 defeat to the Stormers with Emiliano Boffelli coming in for Matias Orlandi on the wing.
"It's another hard game before we make our debut in Super Rugby," said Boffelli.
"It is a good opportunity to correct the things that went wrong against the Stormers. The climate [in Johannesburg] will also be very hot and that's good for us to become accustomed to before we are are in Bloemfontein.
"Wehave to fine tune things before our [Super Rugby] debut. It would be great to play a good game tomorrow so that we can go into the Cheetahs game with confidence."
Jaguares: 15 Joaquín Tuculet, 14 Emiliano Boffelli, 13 Matías Moroni, 12 Jerónimo De la Fuente, 11 Santiago Cordero, 10 Nicolás Sánchez, 9 Martín Landajo, 8 Leonardo Senatore, 7 Javier Ortega Desio, 6 Pablo Matera, 5 Tomás Lavanini, 4 Guido Petti, 3 Ramiro Herrera, 2 Agustín Creevy (captain), 1 Lucas Noguera.
Replacements – from: Matías Orlando, Facundo Isa, Matías Alemanno, Nahuel Tetaz Chaparro, Santiago García Botta, Julian Montoya, Felipe Arregui, Felipe Ezcurra, Santiago González Iglesias, Rodrigo Baez, Gonzalo Bertranou, Joaquín Paz.
Date: Friday, February 19
Venue: Wits Stadium, Johannesburg
Kick-off: 19.00 (14.00 Argentina time; 17.00 GMT)
Referee: Stuart Berry (South Africa)