Juanito believes the 1-0 win over Saudi Arabia was a valuable experience for some of Spain's reserve players.
The Real Betis defender scored the game's only goal on Friday, as Spain won Group H with the one-goal success over The Green Falcons.
The 29-year-old was pleased with his goal in Kaiserslautern and the chance for a run-out in a World Cup finals match, as Spain coach Luis Aragones played an entirely new starting XI against the Saudis.
"The game didn't have a lot of importance because we had already qualified, but it was a chance for the other players to impress," Juanito told Spanish radio.
"We all did the best we could and I was pleased with my performance because it isn't every day you can score a goal in a World Cup.
"We played well enough in the first half, but lost too many balls too easily in the second when we took it a little easy.
"But they were not easy opponents. They made it difficult for us."
Juanito is not bothered by who La Furia Roja will face in the round of 16, as the Group H winners face the runners-up from Group G - with France, Switzerland or South Korea all possible opponents.
"I don't care who we get in the next round, though France are clearly the strongest side we can come up against," he added.
"It's one more little step to (the final) in Berlin. We'll see how it goes."
Another reserve player in Arsenal's Jose Antonio Reyes was pleased with his performance against the Saudis, having set up Juanito's winner with his free kick from the left.
"It was my first match today," said Reyes. "I was quite happy.
"I think I did a good job. We won and that's the important thing.
"I think people can expect a lot more from us. This is just the beginning. This was just our start."
Aragones, meanwhile, felt Saudi Arabia were unfortunate not to get a draw.
"We didn't play too badly in the first half and maybe could have had another goal," Aragones said.
"But we fell apart in the second and were at their mercy.
"They deserved to score a goal and get at least a draw from the match."