Munir, 19, only made the breakthrough into the Barca first team this season, but has already been called up to the La Roja senior team following an injury to Diego Costa.
"He's a great player and he's doing well. He's here with us because he's been with the Under-21 side. We'll help him to adapt as quickly as possible and he's joined us with a lot of enthusiasm. I'm sure he's really looking to making his debut and doing well," he told reporters.
Spain face Macedonia in a Euro 2016 qualifier on Monday.