UPDATED: Agustin Creevy withdrew from the team for personal reasons on Friday and was replaced on the bench by Santiago Socino.
Joaquín Tuculet will run out at fullback in place of Emiliano Boffelli, while Sebastián Cancelliere comes in on the wing for Santiago Cordero. In the midfield, Jerónimo de la Fuente moves from inside to outside centre, where he will line up next to Lucas Mensa.
Ledesma has also picked two new halfbacks in Joaquín Díaz Bonilla (flyhalf) and Felipe Ezcurra (scrumhalf), with Nicolas Sanchez and Tomas Cubelli dropping out of the match-23 altogether.
Upfront, Javier Ortega Desio moves to No 8, while Marcos Kremer is back on the side of the scrum after he started at lock last weekend in Salta, where the Boks won by 46-13.
Tomás Lavanini and Guido Petti will pack down in the middle row at Loftus, behind a new-look front row of Santiago Medrano, Julian Montoya and Mayco Vivas.
Argentina: 15 Joaquin Tuculet, 14 Sebastian Cancelliere, 13 Jeronimo de la Fuente, 12 Lucas Mensa, 11 Ramiro Moyano, 10 Joaquin Diaz Bonilla, 9 Felipe Ezcurra, 8 Javier Ortega Desio, 7 Marcos Kremer, 6 Pablo Matera (captain), 5 Tomas Lavanini, 4 Guido Petti, 3 Santiago Medrano, 2 Julian Montoya, 1 Mayco Vivas. Replacements: 16 Santiago Socino, 17 Nahuel Tetaz Chaparro, 18 Juan Figallo, 19 Matias Alemanno, 20 Tomas Lezana, 21 Gonzalo Bertanou, 22 Benjamin Urdapilleta, 23 Santiago Carreras.