Vicente del Bosque chose to start with a line up including up to five 'squad players' in Buenos Aires and watched a fired up Argentina storm to victory.
Lionel Messi, Gonzalo Higuain and Carlos Tevez had the hosts 3-0 up at half-time, proving perhaps that repairing damaged pride in front of your own fans after a disappointing World Cup was a stronger motivating factor than impressing your boss for a starting place.
It was the first time since August 2000 that Spain had conceded four goals in a match, when they lost by the same scoreline away to Germany in a friendly.
"Defeats hurt, but at the same time they should be beneficial for the team," Del Bosque told reporters.
Spain cruised to a 4-0 win away to Liechtenstein in their opening Euro 2012 qualifier last Friday, but the famous Monumental stadium proved a far tougher test even though it was a friendly.
"These contrasting games are important," he added. "We have to know how to play against weaker teams and the great teams in the same way."
Del Bosque argued the defeat was heavier than they deserved and stood by his decision to field fringe players such as Alvaro Arbeloa and Nacho Monreal in defence and Pepe Reina in goal.
"We can't play the same players every day," Del Bosque said. "We have to remember it's the start of the season. I'm thinking of the clubs but above all else the players.
"There are league and Champions League matches just round the corner."
First-team regulars Fernando Torres, Xavi and Iniesta were all called up for the latest round of internationals despite doubts over their fitness.
Torres, who scored twice in Liechtenstein, did not feature in Argentina and the Barca duo played 45 minutes each.
Argentina fans may have been disappointed, but club managers such as Liverpool's Roy Hodgson and Barcelona's Pep Guardiola will have been a little happier.
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