Chelsea right-back Cesar Azpilicueta, 23, Malaga playmaker Isco, 20, and Atletico Madrid midfielder Mario Suarez, 25, all stepped up in Doha and showed the slow transition to a new generation of players was progressing smoothly.
"They are players who will improve our squad and who have adapted normally to the group without any problems," Spain coach Del Bosque told a news conference.
"They did what they had to do. They were faithful to the characteristics that prompted us to call them up."
The world and European champions shrugged off injuries to first-choice stalwarts such as goalkeeper and captain Iker Casillas, and midfielders Xavi and Xabi Alonso to triumph.
Casillas will not be back after surgery on a finger in time for Spain's World Cup qualifier at home to Finland on March 22, or for the trip to play France four days later.
Barcelona's Victor Valdes was a reliable substitute in goal, however, and is likely to be in the number one jersey when Spain take on the Group I joint-leaders in a clash of huge significance in Paris next month.
While the debutants may not feature against Finland or France, it is highly likely some of them will be taken to Brazil for the Confederations Cup on June 15-30.
"It's two-and-a-half months since we were all together to play a game," added the avuncular Del Bosque, who always places a high premium on dressing room harmony.
"We have six weeks until we play Finland. It was important for us to get together ahead of these games. The most important aspect of it is the contact between the players.
"We should remember what awaits us in March. We start from now preparing for two extremely difficult encounters. If the spirit between us all is healthy and positive we will be closer to succeeding."
Spain are unbeaten in World Cup qualifying but conceded a last-minute goal to draw 1-1 in Madrid, when they took on their closest rivals for the top spot in the Group, France, last October.
"We have had routines established for a long time now, and we have a fairly stable squad," former Real Madrid boss Del Bosque added.
"The important thing is to incorporate new players and not to lose the competitive spirit, whether we are playing a friendly or not. We have to know how to compete. Time with the national team is important, and the players know that."
Thank you for reading 5 articles this month* Join now for unlimited access
Enjoy your first month for just £1 / $1 / €1
*Read 5 free articles per month without a subscription
Join now for unlimited access
Try your first month for just £1 / $1 / €1
Get the best features, fun and footballing frolics straight to your inbox every week.
Thank you for signing up to Four Four Two. You will receive a verification email shortly.
There was a problem. Please refresh the page and try again.