Eddie Jones's Brave Blossoms face Canada, the joint hosts and Fiji over successive weekends from July 18 but the Australian coach was wary of revealing too much ahead of the World Cup match against the Americans on Oct. 11 in England.
"Against America we are not going to show anything. I am treating that like 80 minutes of training," Jones told Kyodo News on Thursday of the Pacific Nations Cup fixture.
"We've beaten them twice over the last two years so we know how to play them. Anything we do is to their advantage not our advantage."
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Japan, who won their first and only World Cup match in 1991, could also end up playing Samoa in the Pacific Nations Cup. The two sides have been grouped with the Americans in Pool B of the Sept. 18-Oct. 31 World Cup.
South Africa and Scotland are the other two teams in the group.
Jones said he would also avoid showing Samoa their World Cup tactics if they end up meeting, pointing at the success of the U.S. women's soccer team for tactical tricks as they smashed Japan 5-2 in the final of the World Cup on Sunday.
"America scored two early goals by keeping the ball on the ground, knowing the Japan side had spent all week training to combat the aerial threat," Jones said.
"It shows that if you can do something tactically clever early on that makes the opposition re-think, it puts you in a good position."
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