Lock Ian Evans has been handed a welcome boost with the news that he will be fit for the start of Wales' World Cup campaign.
Lock Ian Evans hoped to play his first match since December
Evans has been told that he will be out of action for three weeks with a collarbone injury, meaning he misses all of their warm-up games.
But Evans will be fit by the time Wales travel to Nantes for the World Cup.
"We anticipate Ian returning to fitness as we head out to Nantes for the World Cup," said team physio Mark Davies.
Evans picked up a ligament injury to the end of his collarbone during training on Monday.
The Ospreys man was due to face Argentina at the Millennium Stadium on Saturday, but his injury means his place in the Wales team goes to Alun Wyn Jones with Gloucester lock Will James taking up Jones' place on the bench.
Evans, regarded as a key man in Wales' World Cup plans, has not played since dislocating his shoulder last December.
But Davies calmed fears that Evans might be ruled out of Wales' World Cup campaign which starts in September.
He said: "The results of our investigations were the best we could have hoped for, revealing a simple ligament strain to the joint where his collarbone meets the sternum.
"It is a stable injury and will now require rest and treatment with a view to him returning to full training in up to three weeks time."
Wales start their tournament with a Pool B clash against Canada in Nantes on 9 September.
While Evans' injury does not appear serious on first examination, any complications could see Wales left short of locks with Rob Sidoli and Brent Cockbain out of the squad.
Having seen a third-string side crushed by England last week, Wales coach Gareth Jenkins named a strong team to face the Pumas at Cardiff's Millennium Stadium.
World Cup skipper Gareth Thomas leads the side from inside centre, one of only four survivors - including Jones - from the team mauled 62-5 at Twickenham.
Centre partner Tom Shanklin and wing Dafydd James are the other two.
Duncan Jones, Adam Jones and Matthew Rees return to the front row to face the formidable Argentinian forward power.
All we need now is to gain some momentum from our games against Argentina and France
Ian Gough, Jonathan Thomas, Martyn Williams and Alix Popham make up a beefy pack.
In the absence of Shane Williams, James plays on the wing, while James Hook gets another opportunity to show Jenkins that he should be Wales' first choice outside-half with Stephen Jones still struggling with injury.
"We are fitter and stronger than we have ever been before and are set to peak our conditioning levels just as the competition starts," said Jenkins.
"The coaching team has been planning for this ever since we took over in April, 2006.
"All we need now is to gain some momentum from our Invesco Perpetual Summer Series games against Argentina and France at the Millennium Stadium later this month."
Wales' team to face Argentina at Cardiff's Millennium Stadium (18 August):
Kevin Morgan (Dragons): Dafydd James (Scarlets), Tom Shanklin (Blues), Gareth Thomas (Blues, captain), Mark Jones (Scarlets); James Hook (Ospreys), Dwayne Peel (Scarlets); Duncan Jones (Ospreys), Matthew Rees (Scarlets), Adam Jones (Ospreys), Ian Gough (Ospreys), Alun Wyn Jones (Ospreys), Jonathan Thomas (Ospreys), Martyn Williams (Blues), Alix Popham (Scarlets).
Replacements: T Rhys Thomas (Blues), Gethin Jenkins (Blues), Will James (Gloucester), Colin Charvis (Dragons), Mike Phillips (Ospreys), Ceri Sweeney (Dragons), Jamie Robinson (Blues).