The 25-year-old Herrera, who stands at 6ft 3in and weighs over 19 stone, is one of three overseas players in the team selected by head coach Daniel Hourcade, who was appointed in October.
Nicolás Sánchez, who plays for Bordeaux-Bègles in France, will start at out-half alongside captain Martin Landajo, while lock Manuel Carizza from South African outfit the Stormers is the most experienced player in the squad with 40 caps.
The Argentina team also include four players who have won their first caps during the past year - prop Lucas Noguera Paz and centre Jerónimo de la Fuente made their Test bows last month, with winger Santiago Cordero a debutant last November and lock Tomas Lavanini's first game coming against South Africa last August.
Hourcade's charges may lack experience but they have played two recent matches in the South American Championship, running in 10 tries - including four for winger Manuel Montero - during a 65-9 hammering of Uruguay on May 17.
A week later, the Pumas went one better, notching 11 tries as they coasted to a 73-12 win over Chile.
Of the team that started that day in Santiago, full-back Joaquin Tuculet, centre Gabriel Ascarate and the half-backs are retained along with Lavanini in the second row.
Saturday's first Test will be broadcast live on Sky Sports 1 HD (coverage begins at 7.30pm). The teams will play for the Admiral William Brown Cup which is named in memory of the Irish-Argentine Navy admiral William Brown.
ARGENTINA Team & Replacements (v Ireland, Estadio Centenario, Resistencia, Chaco, First Test, Saturday, June 7, kick-off 3.40pm local time/7.40pm Irish time):
15. Joaquin Tuculet (Unattached) 8
14. Santiago Cordero (Regatas Bella Vista) 5
13. Jerónimo de la Fuente (Duendes RC) 2
12. Gabriel Ascarate (Natación y Gimnasia) 12
10. Nicolás Sánchez (Bordeaux-Bègles) 18
9. Martín Landajo (CASI) 28 (capt)
1. Lucas Noguera Paz (Lince RC) 2
2. Matías Cortese (Liceo RC) 5
3. Ramiro Herrera (Castres Olympique) *
4. Manuel Carizza (Stormers) 40
5. Tomas Lavanini (Hindú Club) 5
6. Rodrigo Baez (Liceo RC) 8
7. Tomás de la Vega (CUBA) 9
8. Benjamin Macome (Unattached) 17
16. Julian Montoya (Club Newman) 2
17. Bruno Postiglioni (La Plata RC) 10
18. Nahuel Tetaz Chaparro (La Plata RC) 5
19. Matías Alemanno (La Tablada) 2
20. Javier Ortega Desio (Estudiantes de Paraná) 5
21. Tomás Cubelli (Belgrano Athletic) 22
22. Santiago González Iglesias (Asociación Alumni) 4
23. Lucas González Amorosino (Oyonnax) 30
* Denotes uncapped player