Wales coach Wayne Pivac believes he has learned much about the Six Nations winners' strength in depth during this summer's Test programme.
Pivac has been without a host of senior players due to British and Irish Lions call-ups and injuries for their season-ending matches against Canada and Argentina.
After thrashing Canada 68-12 and then battling back to claim a 20-20 draw against Argentina last weekend, Wales wrap up their successful campaign with the second Test against the Pumas in Cardiff on Saturday.
Pivac has decided to freshen up his side for the game at the Principality Stadium, making seven changes including handing starts to Cardiff half-backs Tomos Williams and Jarrod Evans.
XV CYMRU 🏴 Wales make seven changes for series decider with @lospumas 🇦🇷 🆕 Uncapped Matthew Screech among the replacements. ➥ Pedwar newid yn yr olwyr a thri ymysg y blaenwyr.#HWFN ⑊ #ARGvWAL — Welsh Rugby Union 🏉 (@WelshRugbyUnion) July 15, 2021
"We always planned to get as many of them out there as we could," said Pivac. "It's the last opportunity for us to have a look at them against quality opposition.
"We have learnt a lot in these last four weeks and with some of them it's now putting that into the acid test against a tier-one nation.
"On reflection, I think it has been a season where we are very happy we have been able to win the Six Nations and do a lot of development work throughout the autumn and summer series, which bodes well for the future.
"We saw at the last World Cup, you are going to get injuries and you have to have players with experience coming in. If we can get players with 10-15 Tests under their belt from the last World Cup to this one coming, then it'll have served its purpose."
Williams and Evans have both earned starts after impressing off the bench as Wales fought back to earn a share of the spoils last weekend.
Pivac said he now hopes to see "more of the same" from them.
He added: "Both of those players had strong games when they came on. We were always going to mix and match with the halves, from the first game to this game, so that is exactly what we have done."
Elsewhere in the backs, Tom Rogers comes in on the wing and Nick Tompkins partners captain Jonathan Davies, who has overcome a knock, in midfield.
Up front, prop Gareth Thomas will make his first start and Leon Brown also comes into the front row.
Josh Turnbull gets an opportunity with Aaron Wainwright out injured while Ross Moriarty switches to number eight.
Matthew Screech will get the chance to win his first cap off the bench while fellow replacements Sam Parry and Rhodri Jones will be involved for the first time this summer. Centre Willis Halaholo, who had been an injury doubt, will also be among the substitutes.
Ospreys forward Thomas, whose previous two caps have come off the bench, said: "It is going to be a special day and I'm really looking forward to it. Having a start gives me more time on the field to hopefully show more of what I can do.
"Hopefully I can come out firing and we get a good win against a team we drew with last weekend."
