The 62-year-old is confident in his side's quality ahead of the World Cup next summer but insists they must not allow arrogance to creep into their game
An abject Roja outfit were beaten 1-0 by South Africa in their last match - a friendly in the very stadium where they clinched the 2010 title against Netherlands - and Del Bosque has urged his side not to become complacent ahead of the tournament in Brazil.
"We have very good players to defend the 2010 title, but we should not lose our humility," he told a supporter event at the Spanish national team's training base.
"Of the 31 teams that qualified, I can't see any easy opponents. There are many countries who have been away from big successes and want to win."
Del Bosque went on to stress he will not discount anyone from consideration for a place in the squad next summer, claiming he will look at the form of both established players and young talent when he decides on the party to take to Brazil.
"The youngsters are coming together. We intend to be fair," he added.