Argentina coach Santiago Phelan is surprised Mike Phillips has not been included in the Wales side to face the Pumas.
Bayonne scrum-half Phillips, 30, has to make do with a place on the bench for Saturday's Millennium Stadium encounter. Scarlets scrum-half Tavis Knoyle will instead wear the number nine shirt, but Phelan does not expect Knoyle to be a weak link, particularly given the understanding he has with Scarlets team-mate and fly-half Rhys Priestland.
"Yes, I was surprised, I thought he (Phillips) would be playing and I don't know the reasons (why he has been left out)," Phelan said. "But his replacement is a good player and he has continuity with his club team-mate."
Phelan added: "We know we need to concentrate on all parts of the game as they are in good shape. They have good individual players and we are prepared for a tough game."
Phelan has named a side including veteran centre Felipe Contepomi, with Juan Martin Hernandez moved to full-back as Nicolas Sanchez gets a chance to impress at fly-half.
Gonzalo Tiesi returns in midfield for the first time since the World Cup and Juan Imhoff takes over from Horacio Agulla on the left wing.
Up front, flanker Julio Farias Cabello moves into the second row as a replacement for the injured Patricio Albacete with Leonardo Senatore coming into the back row.
In the front row, Leicester's Marcos Ayerza benefits from the retirement of Rodrigo Roncero and the absence of Francisco Gomez Kodela to start on the loosehead side of the scrum alongside Eusebio Guinazu and Juan Figallo.
Kodela, his Biarritz colleague Marcelo Bosch and Montpellier's Lucas Amorosino, were among those unavailable for selection as part of an agreement with the clubs in France, although they will return for fixtures against France and Ireland.
Phelan said: "For this tour we had a special agreement with the French union about not taking more than two players from each club (for each game), and in some clubs we have more players so we had to think what was best for this game as they have club games in France."