Stajic, who was an interested spectator at the round of 16 match, said but that his team has an unwavering belief that it can continue its amazing run in the tournament when the two teams meet in Edmonton on Sunday (AEST).
"Their passing and movement off the ball is probably the best of any team at the World Cup, so we've got a big assignment on our hands – the current world champions and a very good team," Stajcic said of Japan.
"But as I've said before we're a very good team as well and we've been dangerous against everyone and there's no reason we can't be dangerous when we play Japan and be a real threat.
"We know we have to be at our best to challenge these great nations that we've played already like United States, Sweden, Brazil and now Japan – that's four of the World Cup finalists in this millennium.
"I'm confident we can beat them but it's going to be an extremely tough match and we will need to be at our best for 90 minutes."
After playing against Japan twice at last year's AFC Women's Asian Cup at a time Stajcic had just taken charge of the team on an interim basis, the Matildas boss says his team has progressed considerably since.
"I think we learnt from the Asian Cup. We had a 2-2 draw with them after we were 2-nil up and we lost the final 1-0 off a corner," he said.
"I think the biggest thing we've learnt is the belief we have in the team, I think if we play to our potential we can match it with the world champions.
"That was 12 months ago and we've grown a lot since then on and off the field."
