Ireland must look to hit maximum against Japan

This time around, the Irish will not be unsettled, like they were against Australia, by the physicality the Japanese will bring to the contest.

They simply don't have the tools to break Ireland's will by going toe-to-toe.

The skill here is for Tierney to figure out how many changes are needed ahead of what will amount to a showdown against France for a semi-final berth next Thursday. Of course, it is not beyond the bounds of possibility that the Wallaroos could do Ireland a favour by unseating Les Bleus tomorrow.

The lop-sided nature of the competition meant there was just one truly competitive match on the first day as the Irish just about held out the Australians (19-17) in a pulsating encounter in Pool C.

The opening night jitters have been well and truly shaken out and, from now on, the hosts must start to improve dramatically.

"There was probably some nerves," admitted full-back Hannah Tyrrell.

"It is a World Cup on home soil and we wanted to get off to a good start. They just had big units.

"We were really going hard at them and there was a lot of turnovers from both teams.

"Thankfully, we got a bit of momentum, the few tries and we finished strong."

Ireland will have to look for the maximum return of five points against Japan, suitably demoralised from Wednesday night.

"They are very well drilled," argued former Dublin footballer Tyrrell.

"They are very low tacklers and they like to swarm the ruck.

"We have a couple of players and tactics that we think will work against them, so we can't wait."

All of that aside, Ireland should have way too much size, structure and strength for the Asian nation.

It will be all about how the home country binds the set-piece together and shows a more clinical edge in attack.

They are the oldest, most experienced team in the tournament.

Given that, there is the strong sense that the others know how to snuff out Ireland's strengths. For instance, centre Jenny Murphy, doubtful for tomorrow, and Allison Miller are, by far, their best weapons out the back.

The lack of explosive threats in the back division means they can be coralled more easily.

It is down to the forward pack to dominate possession, win the gain line, suck in defenders to create holes on the fringes or space on the outside.

Ireland have to come away with a clean bill of health to put them in the best possible position to challenge France next Thursday.

The least Ireland would wanted is to make the final four.

VERDICT: Ireland