The 21-year-old Jaguares back was one of three uncapped players named in the Pumas matchday squad along with flanker Santiago Grondona and fellow centre Lucio Cinti, who could make their debuts off the bench.
Chocobares will line up with Matias Orlando in midfield at Western Sydney Stadium ooutside the experienced halfback pairing of scrumhalf Tomas Cubelli and flyhalf Nicolas Sanchez.
"It is a good opportunity to see how Santiago reacts," Ledesma told reporters on Thursday.
"It has surprised all of us how he came physically prepared after the pandemic and is very consistent. He has shown good energy and attitude in all our training sessions."
Prop Francisco Gomez Kodela will make his first test start for eight years in the front row of a pack otherwise largely unchanged from Argentina's last test against the United States at the World Cup in Japan more than a year ago.
Unlike their Tri-Nations rivals New Zealand and Australia, the Argentines have not played any competitive rugby since the Super Rugby competition was halted by the COVID-19 pandemic in mid-March.
Ledesma said the squad had, however, made the most of being locked up together in a bio-secure training camp back home in South America and then in quarantine after arriving in Australia.
"For the last three months, we've been 24-7 with each other, we haven't been with our families for a while now," he added.
"Tough times either separate you or bring you together. For us it has been great. We've really profited from enduring this situation to create a culture."
Team: 15-Santiago Carreras, 14-Bautista Delguy, 13-Matias Orlando, 12-Santiago Chocobares, 11-Juan Imhoff, 10-Nicolas Sanchez, 9-Tomas Cubelli, 8-Rodrigo Bruni, 7-Marcos Kremer, 6-Pablo Matera (captain), 5-Matias Alemanno, 4-Guido Petti, 3-Francisco Gomez Kodela, 2-Julian Montoya, 1-Nahuel Tetaz Chapparo
Replacements: 16-Facundo Bosch, 17-Mayco Vivas, 18-Santiago Medrano, 19-Santiago Grondona, 20-Tomas Lezana, 21-Gonzalo Bertranou, 22-Lucio Cinti, 23-Santiago Cordero.