Bringing in Casey, Balacoune, Baird, Timony, Jensen to start has lowered the age-profile considerably

Andy Farrell has taken a very un-Andy Farrell like risk with team selection for Argentina at the Aviva tonight.

This, in turn, makes it one of the most fascinating Ireland rugby games in the November window in recent times.

True, the Nations Championship hasn't captured everyone's imagination just yet but it could have by the middle of the month - if Ireland beat the Pumas.

As it stands, the coach seems to have spent the post-summer months brooding about something, and the team selection here suggests it was about the first XV's age-profile.

If he thinks the unit was showing its age when losing 40-19 to the All Blacks in Auckland last time out he may have decided this was not a XV, one year older, he wants to kick off the Rugby World Cup with.

And it may be not so much about dropping people but acknowledging 34 year-olds such as Jamison Gibson-Park and Jack Conan need time/play management and that it might be a good idea to upskill those coming behind.

Craig Casey, for instance, starts ahead of Gibson-Park; Nick Timony is chosen ahead of Josh van der Flier; Sean Jensen and Ryan Baird get to start as Conan and Caelan Doris are unavailable.

Sam Illo has been preferred on the bench to Finlay Bealham while in a delayed re-jig Robert Baloucoune is in for James Lowe.

That's five significant thirty-somethings - JGP, JVDF, Conan, Bealham and Lowe - not starting here.

Even so, the team isn't startlingly younger as there is still a significant thirtysomething presence on the team - Robbie Henshaw, Stuart McCloskey, Andrew Porter, Tadhg Furlong, Tadhg Beirne and Timoney (two years younger than van der Flier) and he still isn't able to work out how to use Jamie Osborne or Bryn Ward/James McNabney to best effect.

But selection signals Farrell might be willing to take a step back in this set of games in the hope of moving two steps forward for the Six Nations.

There is another side to the coin. Winning against Argentina has it's prize in that with the uncompetitive Fiji side next up in Dublin, two wins would generate excitement with regard to the Nations Championship.

Ireland currently sit in fourth in the Northern Hemisphere conference, but two wins would likely propel them to first or second with the prize for beating South Africa in third game making the first/second placed final.

If Ireland have ridden the storms of scorn for not being able to get past the Rugby World Cup quarter-finals for long enough and to make a Nations Championship final might not quite the equivalent of a World Cup final but it is one hell of a step above a World Cup quarter-final.

Moreover, a weather-eye kept on whether skipper Dan Sheehan, selected at hooker for Argentina but who played as no8 in a recent Leinster game, is asked to do any back-row work as the game progresses.

And while it is hard to know if this isn't some sideshow with no relevance to Ireland there seems no curbing Sheehan's enthusiasm at training where he liks to lend a hand.

"I think I did a few sets in back-row just in training last week and sort of though the training week but that was just we had looked around and we only had 14 on the pitch so I had to jump into back-row."

These jobs at no2 and no8 have their differences.

"You are probably doing a bit more grunt work in the middle of the pitch, whether it be exit carries or just trying to truck it up.

"I found myself like 10 minutes into the Leinster-Munster game, probably with half the stats already gained that I usually get in a game.

"And I thought it was nice in that I felt I got involved early; I got myself into the game, I wasn't waiting 20 minutes to have a first big piece within the game.

"I'm probably used for some tighter, dirtier work, which is perfectly fine but I always enjoy sort of strike plays and the attacking side of rugby and I enjoyed the week of seeing how it worked and how we can sort of figure out defence and stuff with the backs."

Still, it is an extraordinary thought that the captain might be asked to slot into the back-row given Tadhg Beirne is already on the pitch and van der Flier is on the bench. Don't bet on it.

Argentina have won just once in their last four outings, drawing with Australia and losing to Australia (by six points), South Africa (by seven) and England (by seven).

This was preceded by a 35-21 win over Wales and losses to Scotland and England by nine and four points respectively - they sure know how to keep the scoreboard close.

Ireland: Hugo Keenan; Rob Baloucoune, Robbie Henshaw, Stuart McCloskey, Mack Hansen; Sam Prendergast, Craig Casey; Andrew Porter, Dan Sheehan (capt), Tadhg Furlong, Joe McCarthy, Tadhg Beirne, Ryan Baird, Nick Timoney, Sean Jansen. Replacements: Rónan Kelleher, Tom O’Toole, Sam Illo, James Ryan, Josh van der Flier, Jamison Gibson-Park, Ciarán Frawley, Bundee Aki.

Argentina: Juan Cruz Mallia; Bautista Delguy, Justo Piccardo, Santiago Chocobares, Mateo Carreras; Tomas Albornoz, Gonzalo Garcia; Boris Wenger, Julian Montoya (capt), Francisco Morena; Guido Petti, Pedro Rubiolo; Juan Martin Gonzalez, Marcos Kremer, Pablo Matera. Replacements: Leonel Oviedo, Mayco Vivas, Joel Sclavi, Efrain Elias, Juan Martin Scelzo, Simon Benitez Cruz, Geronimo Prisciantelli, Lucio Cinti.