The veteran coach agreed that some of his players may be frustrated with their lack of playing time, but insisted they must accept his decisions whether they are starting or not
Del Bosque faced intense criticism for his decision to deploy Cesc Fabregas as a false No.9 and leave Fernando Torres on the bench for the match against the Italians, which ended in a 1-1 draw.
"There is discussion and debate because this is football," Del Bosque told AS. "But there are several options which are there for you to use.
"You have a certain number of players and a playing system and you use what you think that is best, based on your characteristics and a little bit about your opponent.
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The 61-year-old was asked if he was not afraid that tension could grow in the squad due to the fact that some of his men have not yet played a single minute at Euro 2012.
"This is football, not catechesis," he added. "Everyone feels they can be a starter, and I understand if they are not happy.
"Some of them have not even sat on the bench. Everyone feels like a starter because that is what they are.
"Moreover, we do not know what could be in for them in the rest of the competition."
Spain are now preparing for their quarter-final contest against France, a side Del Bosque has shown much respect for.
"France usually play in a 4-2-3-1 system and I do not think they will change it," he said.
"They have very good attackers with a lot of quality, from Hatem Ben Arfa to Florent Malouda, also Samir Nasri, Franck Ribery, Jeremy Menez and Karim Benzema.
"They are a great side who also know what it feels like to win World Cups and European Championships.
"Every team left in the competition is tough, but so are we."