Del Bosque put the defeat down to Brazil's physical shape - the hosts were better rested and pressed energetically. He also bemoaned their fouling, with Brazil's forwards ordered to halt Spanish counter attacks with tactical fouls.
"They were better. We congratulate them. We had a touch of bad luck in the first two minutes of both halves and in the final minutes of the first half, but I don't want to make excuses. They were better," said the Spain coach.
"I think we've had a good Confederations Cup. I'll stick with the positive. Our players gave their all.
"Neymar and the rest had much more energy, and that was reflected in every play. The only thing I was not too happy about was the number of Brazilian fouls but that came because they put pressure on us all over the field. But we have no complaints.
"When we look at our track record, we can be proud. Today we have been defeated, be we won't just sit back and accept it. We will fight back, we have good players and I don't see the need to change just because we were well beaten for once."