Japan and Australia head into Saturday's test match at Nissan Stadium knowing they both need to put behind them less than average performances against invitation sides.

The Brave Blossoms lost 47-27 to a World XV last weekend, while the Wallabies — who beat the All Blacks two weeks ago — defeatedthe Barbarians 31-28.

"It's hard to organize a good BBQ in four days and we had a test against some very good players," was Japan coach Jamie Joseph's assessment of the defeat on the back of a short training camp.

While of the Wallabies' narrow win against rugby's most famous invitation side he said, "they rested some of their senior players and almost paid the price."

Both sides show plenty of changes to their starting XV and Joseph is hoping the return of some senior players will help the team adapt to the defensive pattern installed by new assistant coach John Plumtree.

"We have a game under the belts and the return of the senior players will be crucial," Joseph said. "But we will need to play at the level we expect for the full 80 minutes."

Japan was dominated physically by the World XV, particularly in the second half. And captain Michael Leitch said his side would need to be much more competitive at the breakdown.

"They have one of the best back row forwards in the world," Leitch said of Australia captain Michael Hooper. "So matching them at the breakdown will be difficult."

And when they do win the ball, the Brave Blossoms will need to use it wisely.

"When we get the ball we need to create momentum and get behind them," explained Joseph. "When we do that we have the skill and speed to score against very good sides."

Key to using the ball well will be flyhalf Rikiya Matsuda.

The 23-year-old has been in outstanding form at Panasonic Wild Knights but has spent most of the season at inside center.

"It is a big test for him and while he is a gifted player, running the cutter is different," Joseph said.

Fortunately the return of Harumichi Tatekawa — who was expected to miss the first two games of the autumn campaign with a strained groin — means Matsuda has a world-class operator outside him.

"The doctor gave us a different message," was Joseph's explanation for Tatekawa's surprise inclusion.

Tatekawa's experience, however, is in marked contrast to five members of the 23-man squad who will all be playing their first game for their country.

Kazuki Himeno, in particular, can expect a tough baptism of fire as he has been forced to move from flanker, where he has played so well for Toyota Verblitz, into the second row.

"You don't see too many 6-foot-8 (2-meter) guys in Japan and I can't control genetics but it is an area where we need more experience," Joseph said of the shortage of test-match quality locks.

While saying "I am not going to give away any secrets about how we will attack Japan," Hooper did say the lack of tall timber was an area his side hopes to exploit.

"To be successful in a test match the set piece is much of the battle and it would be foolish not to say we've come in with that as one of our focuses."

The 26-year-old flanker also said his side would look to use its size — the Australian forwards are on average 5 cm taller and the backs 7 kg heavier than the Japanese — to dominate the hosts.

"The mindset we have is one of a lot of physicality," he said. "Aggression, leg drive, things we talk about frequently, to make them retreat hard and make it tough for them."