Cardiff Blues centre Cory Allen will make his Test debut when Wales tackle Argentina at the Millennium Stadium on Saturday.
At the other end of the scale, 20-year-old Allen's Blues colleague Gethin Jenkins will become the fourth player to win 100 Wales caps after Stephen Jones, Gareth Thomas and Martyn Williams.
Wales coach Warren Gatland has made four changes from the side beaten 24-15 by South Africa last weekend.
Allen replaces an injured Jonathan Davies alongside Scott Williams in midfield, while Ospreys fly-half Dan Biggar starts instead of Rhys Priestland.
In the pack, Scarlets front-row prospect Rhodri Jones takes over from Adam Jones, who has a calf muscle problem, and an ankle injury sidelines flanker Dan Lydiate, so Justin Tipuric wears the number seven shirt and skipper Sam Warburton moves to blindside.
Rhodri Jones, 21, first featured for Wales against the Barbarians last year, and he was also part of the 2013 summer tour to Japan. He has won two caps, but was only called up by Gatland last Sunday as squad injury cover.
Biggar, meanwhile, was the Wales number 10 throughout last season's title-winning RBS 6 Nations campaign, taking his opportunities well while Priestland was sidelined with an Achilles tendon injury.
The highly-rated Allen, who cut his representative teeth on the international sevens circuit with Wales, has a golden chance to impress Gatland building towards the autumn finale against Australia on November 30.
Liam Williams, who went off injured against South Africa, has been named on the left wing, with Leigh Halfpenny and George North retained at full-back and right wing respectively.
The Wales bench includes uncapped Scarlets prop Samson Lee, who was another call-up last weekend, and former Wales captain Ryan Jones.
Wales XV to face Argentina: L Halfpenny; G North, C Allen, S Williams, Liam Williams; D Biggar, M Phillips; G Jenkins, R Hibbard, Rhodri Jones, B Davies, A-W Jones, S Warburton (capt), J Tipuric, T Faletau.
Replacements: K Owens, P James, S Lee, L Charteris, Ryan Jones, Lloyd Williams, J Hook, A Beck.