The Scarlets prop will make his third Welsh appearance at the Millennium Stadium, packing down alongside Richard Hibbard and Gethin Jenkins.
Jones replaces his namesake Adam in a change from the front row which took on South Africa last weekend. The relative inexperience of Jones, who made his Wales debut against the Barbarians last summer, contrasts markedly with Jenkins, who will win his 100th cap against the Pumas.
“If Rhodri wasn’t ready we would not put him out there,” said McBryde.
“It’s a long term plan obviously but in the time he has been at tighthead, he has shown enough for us to be selected. He played for us against the Brumbies on our tour of Australia and did outstandingly well.
“He hasn’t had much of an opportunity at regional level but he’s been chipping away and fully deserves this opportunity.
“Argentina are a formidable pack, there’s no getting away from that. However, sometimes playing international rugby at tighthead is easier than playing at Premiership level.
“This is another big stride forward in Rhodri’s development.”
In the only other change to the pack for tomorrow’s game, Justin Tipuric comes in for Dan Lydiate with captain Sam Warburton moving to blindside. But it’s Jenkins, who will join Gareth Thomas, Stephen Jones and Martyn Williams in the list of 100 capped Welshmen, who will be the centre of attention.
“Gethin is quite a serious character, that’s to put it kindly,” said forwards coach McBryde.
“He’s been able to adapt to several different laws and to play at the top level for so long in the position he has is a glimpse of how intelligent a rugby player he is.
“He’s been able to expand his game and last week I thought he was outstanding. He was the pick of the forwards in my opinion in terms of his work rate and effectiveness.
“He’s a bit more comfortable in speaking to the team now. It doesn’t come naturally to some people and has a wealth of experience. We are benefitting from that both as coaches and as a team.
“Hopefully tomorrow will go well for Gethin because he truly deserves it.”
