Japan head coach Jamie Joseph said before Saturday's win over Tonga that he was "80 percent" certain of who would make up his Rugby World Cup squad when he names it on Aug. 15.

But he admitted after the gritty 21-16 victory over the 'Ikale Tahi at Hanazono Rugby Stadium that, with just one game remaining before he makes the final cut, there would be some sleepless nights.

Japan head coach Jamie Joseph (C) shakes hands with replacement back Rikiya Matsuda after beating Tonga in a rugby test match at Hanazono Rugby Stadium in Higashiosaka, western Japan, on July 29, 2023. (Kyodo)

"It will be difficult to decide who to leave in and who to leave out at the World Cup. We want to perform at our best and take our best athletes with us," he said.

One thing is certain -- the squad is unlikely to be exactly the same as he envisaged when the players went into camp in June.

The superb form of two newcomers, lock Amato Fakatava and center Tomoki Osada, must have cemented their place in France, while the return from injury of Ben Gunter and Tevita Tatafu means there will be some difficult decisions when it comes to choosing which back-row forwards will make the trip.

"Osada is a player of the future," Joseph said. "He has really impressed us. Every time he has come on he has made an impact and he did his family and team proud. He is very fit, very fast and very smart."

While of Tatafu and Gunter, whose physicality was evident to all in the crowd of 21,138, he said "they showed signs they are going good."

Fakatava -- who was playing against three of his cousins in the Tonga side -- was involved in the last-minute play that ultimately helped Japan win Saturday's game.

The lock raced back to help out in defense following a sensational tackle from Kotaro Matsushima after an intercept looked to have given Tonga center Afusipa Taumoepeau the chance to win it at the death.

"You could see at the end when the injured player Matsushima got off the ground to make that last tackle and our lock Fakatava getting back after 79 minutes of hard work desperately trying to help the team," Joseph said.

"It's a really good sign of where we are about to go. I am proud of how hard they have worked and they really had to work for 80 minutes to get the win."

For Matsushima, the tackle was a form of redemption following a poor performance the previous week.

"I collided with my opponent and couldn't breathe," he recalled of the situation, which had initially looked as if Japan were about to score an 80-meter try to seal the game.

"I was the only one there, so I had no choice but to go. Winning and losing are completely different mentalities. The team is definitely going in the right direction."

The tackle certainly impressed Japan captain Kazuki Himeno.

"I think Matsu's defense at the end shows the bond that exists in this team."

That bond was down to Joseph going back to the tried and tested.

"This week we took the pressure off the players and talked about what it really means building and playing for each other," Joseph said. "It's been a recipe for success for all my coaching in the past, getting the balance right on and off the field."

But he also pointed out that fans and the media need to remember the bigger picture.

"As coaches we are building a team to perform at the World Cup. This is just part of the process."

So with just 160 minutes of rugby remaining -- against Fiji on Aug. 5 and Italy on Aug. 26 -- before they kick off their World Cup campaign against Chile in Toulouse on Sept. 10, can Japan repeat their 2019 heroics and reach the knockout stage?

"My own personal opinion is that Japan of three or four years ago were a lot stronger," said Tonga coach Toutai Kefu. "Four years ago they beat us by 40 or 50 points and made a big impact at the World Cup."

But he added that Japan had a poor run of injuries and that "they have been training very hard and they will get better and better, I have no doubt."

Whether they have improved enough to beat England and Argentina -- who lost to reigning world champions South Africa by just one point on Saturday at altitude in Johannesburg -- not to mention get revenge over Samoa, remains to be seen.


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