Rugby World Cup 2019: Japan scrum against 10 to prepare for Springboks

Japan's rugby team players practice ahead of their match against Scotland, Saturday, Oct. 12, 2019. Photo / AP

Japan's pack have been scrummaging against 10 men in training this week to simulate the challenge they will face against the Springboks in their World Cup quarter-final on Sunday.

Reserve hooker Takuya Kitade revealed the innovative measure as Japan look to shock the world again after wins against Ireland and Scotland in the pool stages.

"They [South Africa] tend to have a bigger pack compared to us so, to push our team even harder than during games, we [the replacements] go with 10 against the team's eight," Kitade said.

Japan accept they cannot match South Africa for strength. The average weight of Japan's starting pack in their win over Scotland last weekend was 109kg.

That compares with an average of 117.25kg for South Africa's starting pack in their defeat by the All Blacks.

Their success has been built on speed and accuracy in attack, allied to a ferocious work rate and fitness levels which are through the roof.

Flanker Uwe Helu said Japan would have to "trust in their gameplan" and not be sucked in to playing "as individuals" to stand any chance against a team to whom they lost 41-7 only last month.

"We learned if we go as individuals, you are wasting your energy against their physicality," Helu said. "But we're much more confident now. We'll have a few tricks, and we have to beat them by speed.

"We build up where we know the space is," he said. "We're trying to identify specific defenders and exploit them.

"They [South Africa] are different from other teams. They come in twos and threes when they attack. We need to, when we do attack, attack as a team. And when we do defend we need to adjust and defend as a group.

"It doesn't matter if you've got to make 200, 300 tackles. No matter what's coming, you've got to keep tackling."

Helu said Japan were relishing the opportunity to prove the doubters wrong again.

"No one expected us to make the top eight," he said. "No one will even look at us to win this game this week. So it's another chance to prove people wrong."