With Matthew Rees ruled out of the World Cup due to a neck injury and current captain Sam Warburton rested, Ospreys number eight Jones takes the reins.
Wales coach Warren Gatland has made nine changes from the side that beat England 19-9 in Cardiff three days ago.
There are first starts of the three-Test World Cup preparation period for full-back Lee Byrne, wing Leigh Halfpenny, scrum half Tavis Knoyle, hooker Richard Hibbard, prop Adam Jones and flanker Martyn Williams, who wins his 99th cap.
And on the bench, Sale Sharks' back-row forward Andy Powell will be looking for a final chance to impress Gatland before the 30-man World Cup squad in announced next Monday.
Gatland admitted he picked a side which would enable him to cast an eye over some players who are still looking to secure a World Cup berth.
He said: "Criteria for selection has been about putting together a side to win the game, but also about giving some players the opportunity to impress and, therefore, bid for selection for the World Cup.
"In some areas we are also looking at combinations with that opening game against South Africa on 11 September always kept in mind.
"Beating the Pumas on Saturday would also mean we retain that all important winning momentum going into the World Cup.
"But there are still many places up for grabs on that plane to New Zealand and the players all know they need to perform against the Pumas in order to further their own as well as the national cause."
Wales team to play Argentina in Cardiff on Saturday.
L Byrne (Clermont Auvergne), L Halfpenny (Cardiff Blues), J Davies (Scarlets), J Roberts (Cardiff Blues), G North (Scarlets); J Hook (Perpignan), T Knoyle (Scarlets); P James (Ospreys), R Hibbard (Ospreys), A Jones (Ospreys), B Davies (Cardiff Blues), A-W Jones (Ospreys), D Lydiate (Newport Gwent Dragons), M Williams (Cardiff Blues), R Jones (Ospreys, captain)
Replacements: H Bennett (Ospreys), R Bevington (Ospreys), A Powell (Sale Sharks), J Tipuric (Ospreys), L Williams (Cardiff Blues), S Jones (Scarlets), A Brew (Newport Gwent Dragons).
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