The 19-year-old has burst onto the scene with Barcelona this season, quickly becoming one of the most talked-about youngsters in European football.
He received a surprise call-up into the latest Spain squad, but had also been eligible to represent Morocco through his father.
It had been claimed that Munir wanted to represent Morocco, but Del Bosque has said that the teenager "chose" to be with Spain.
"The only reason Munir played is that he was the only player in the squad who hadn't. They all played except for Kiko Casilla," Del Bosque told AS after the player make his competitive Spain debut in last night's 5-1 win over Macedonia.
"We gave him a chance from the Under-21s. I imagine he has a Moroccan feeling but he was here because he chose to be."
Munir scored on his first-team debut for Barcelona last month.