Former Brazilian star Zico says he expects Japan to give the hosts a run for their money in Saturday's Confederations Cup opener.
Zico had a spell coaching the Blue Samurai and feels the Asian champions are not too far behind the South American stars in the pecking order.
"There's every chance of this game being one of the toughest ever between the two sides, and that's for two reasons," said Zico.
"Firstly, the Japanese are getting stronger all the time, with more and more players in leagues like Germany, Italy, England and Russia.
"Secondly, Brazil are still looking for their best starting XI and the right formation.
"Now that they've reached the World Cup, the Japanese should be more relaxed going into the game, though I think they still find it hard going against South American sides. All in all, it should be a fascinating game," Zico told FIFA.com.
But Zico warned Japan faced a huge challenge.
"The Japanese have real problems when they come up against teams with a bit of initiative and creativity," he said.
"When a Japanese player prepares for one thing and something else happens, like a dribble or a piece of improvisation or individual skill, then it tends to throw them off their game," he explained, noting that that could work in favour of the likes of home playmaker Neymar.
"It's that kind of initiative that Japan very often lack, the idea that you can make a mistake and take risks as a result.
"It's a cultural thing and it was something I went on about all the time. But you won't see them trying things very often because they've got it into their heads that they can't make a mistake of any kind."
Yet Zico says Brazil do not impress him particularly right now.
"We're not compact enough. England didn't score twice (in the 2-2 friendly draw on June 2 in Rio) from outside the area by chance. That's dangerous against a team with players who can shoot from distance, like Honda, (Yasuhito) Endo and (Makoto) Hasebe."