The world and European champions thrashed Liechtenstein 6-0 on Tuesday to qualify for the finals, but Torres was dropped to the stands as David Villa and Alvaro Negredo both scored twice and Sergio Ramos and Xavi completed the rout.
"There were ten players who didn't play," Spain coach Vicente del Bosque said when asked about the surprise decision to leave Torres out.
"He is an important player, but the people selected for the national team are those who do well for their clubs, not the other way round."
Torres has scored 27 times for Spain, including the only goal in their Euro 2008 final win over Germany, but was short of match fitness after injury and contributed little to last year's victorious World Cup finals campaign.
The 27-year-old continued to struggle for form in the Premier League last season when a high-profile transfer from Liverpool to Chelsea failed to spark a change in fortunes, and he still has only one goal to his name at Stamford Bridge.
Over the last year he has only managed to find the net once for the national team, in a June friendly against the United States, and the competition to be Villa's strike partner is heating up.
Barcelona's Villa, Spain's all-time top scorer, took his tally to 49 in Logrono on Tuesday while Sevilla's Negredo bagged his third goal in two matches, his fifth in seven.
Athletic Bilbao's Fernando Llorente and Valencia's Roberto Soldado, who notched a hat-trick on the opening day of the La Liga season, are also pushing hard for the trip to Poland and the Ukraine.
Former Real Madrid youth team forward Negredo, played down the significance of Torres's relegation to the stands.
"He came down to the dressing room after the game and congratulated me," Negredo told sports daily AS.
"I'm not going to enter into whether he was annoyed or anything, it was a great gesture to congratulate me for the goals.
"I would understand it if he was, because it isn't much fun to come and not play a single minute, but he is a great colleague and is one of the captains of the national team."
