Lionel Messi sat out Argentina's 2-0 victory over Italy in Manchester on Friday, while the injured Sergio Aguero was officially released from the squad.
Messi is still likely to play on Tuesday against Spain, but the Barcelona star said before the game that he has been battling some muscle fatigue in his legs, and Argentina did not risk him at the Etihad Stadium.
"I've been having trouble for some time in the adductor," Messi told TyC Sports. "During the last training, I felt the problem was still there so we decided that it is better to clear everything for what's coming.
"I wanted to play, but there's still a long way to go until the World Cup and also with my club, so we decided to sit this game out and hope it will be good to play against Spain."
Argentina went with a midfield of Angel Di Maria, Giovani Lo Celso, Lucas Biglia, Manuel Lanzini and Leandro Paredes behind forward Gonzalo Higuain against Italy, who started goalkeeper Gianluigi Buffon in his return from a brief international retirement.
Aguero also missed out on Friday's game, and he will not travel to Madrid for Argentina's next friendly either, the country's federation announced.
The Manchester City striker will stay with his club to continue treatment on the knee injury which forced him out of last week's Premier League game at Stoke.
Aguero has spent this week with his Argentina teammates while they have been based at the City Football Academy in Manchester ahead of Friday's friendly.
However the the 29-year-old, who has scored 30 goals in all competitions for City this season, has not played a full part in any training sessions.
A tweet from Seleccion Argentina read: "Sergio Aguero will be released from the group to continue the recovery of his left knee."
Earlier on Friday, a source told ESPN FC that Messi and Argentina would be training at the Valdebebas training ground of Barcelona's arch-rivals Real Madrid from Saturday until Tuesday.