Scrumhalf Craig Casey was chosen ahead of Jamison Gibson-Park in Farrell's side for the test in Dublin.
Former World Rugby Player of the Year Josh van der Flier was replaced in the starting lineup by Nick Timoney as the Ireland coach seeks to widen the selection pool with the 2027 World Cup in Australia less than a year away.
“Craig deserves to play in a big game at the start of the season, to have the responsibility to be in charge of the week and take responsibility for how we play on Friday,” he told a press conference on Wednesday after naming his line-up.
“We need him to be able to have the opportunity to do that. Plus he’s been playing pretty well himself. He knows the competition is there but he’s got the shirt so it’s up to him to make a good first impression.”
Timoney will be the openside flank.
“Certainly last year he grabbed hold of the understanding of what he can bring and what international rugby is all about,” Farrell said of the 31-year-old Ulster loose forward, who made his test debut five years ago.
“We saw a consistency within that. He brings a lot not just to our game but in different positions as well. Nick gets to wear the seven jersey for the first game and I’m sure Josh will have something to say about that in the coming weeks as well.”
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Ireland take on Fiji next weekend where Farrell is expected to give opportunities to others on the fringes of selection.
“You have to keep them hungry as well,” he said of squad players.
“They will stay hungry no matter what, because that’s the type of people that they are, but you’ve got to make sure your squad is your strength, certainly for what’s coming up in the next 12 months. It’s important that we keep feeding that.
“If ever a player feels comfortable, we’re failing the group, but we’ve not got those players anyway. I don’t think people are comfortable, just by their nature, but if you want to keep ambition growing as a group then you’ve got to keep the ambition within the individual,” Farrell added.
Argentina team:
Starters: 15-Juan Cruz Mallia, 14-Bautista Delguy, 13-Justo Piccardo, 12-Santiago Chocobares, 11-Mateo Carreras, 10-Tomas Albornoz, 9-Gonzalo Garcia, 8-Pablo Matera, 7-Marcos Kremer, 6-Juan Martin Gonzalez, 5-Pedro Rubiolo, 4-Guido Petti, 3-Francisco Moreno, 2-Julian Montoya (captain), 1-Boris Wenger.
Replacements: 16-Leonel Oviedo, 17-Mayco Vivas, 18-Joel Sclavi, 19-Efraín Elias, 20-Juan Martin Scelzo, 21-Simon Benitez Cruz, 22-Geronimo Prisciantelli, 23-Lucio Cinti.
Ireland team:
Starters: 15-Hugo Keenan, 14-Rob Baloucoune, 13-Robbie Henshaw, 12-Stuart McCloskey, 11-Mack Hansen, 10-Sam Prendergast, 9-Craig Casey, 8-Sean Jansen, 7-Nick Timoney, 6-Ryan Baird, 5-Tadhg Beirne, 4-Joe McCarthy, 3-Tadhg Furlong, 2-Dan Sheehan (captain), 1-Andrew Porter.
Replacements: 16-Ronan Kelleher, 17-Tom O'Toole, 18-Sam Illo, 19-James Ryan, 20-Josh van der Flier, 21-Jamison Gibson-Park, 22-Ciaran Frawley, 23-Bundee Aki.