Ireland need a bonus-point win over Samoa in their final World Cup Pool A game in Fukuoka to guarantee themselves a quarter-finals spot.
The build-up to Saturday's match has been overshadowed by the disruption caused by Typhoon Hagibis and concerns over the Hakatanomori Stadium pitch.
Sunday's match between Pool A rivals Japan and Scotland is in major doubt.
If Ireland fail to secure five points against Samoa, their fate will be decided by the outcome in Yokohama.
Henshaw to have first World Cup involvement
Ireland coach Joe Schmidt includes centre Robbie Henshaw for his first involvement in the World Cup after he missed the opening three Pool A games because of a hamstring injury.
Henshaw's inclusion is one of 11 changes from the uninspired 35-0 win over Russia with only Johnny Sexton, Bundee Aki, Keith Earls and Tadhg Beirne retained, although the latter switches from lock to the back row.
Seven forwards changes include the return of skipper Rory Best who will be partnered by Cian Healy and Tadhg Furlong in the front row.
Schmidt's likely plan would have been to rest several of his frontline players in the final Pool A game only for the shock defeat by hosts Japan to rip up the script.
Samoa's slim chances of progressing to the knock-out stages were ended in a defeat by Japan last Saturday.
Steve Jackson makes just two changes to his side for their final game in Fukuoka, with Logovi'i Mulipola and Teofilo Paulo coming in to the pack.
In their last two games, against Scotland and Japan, Samoa have put in spirited first half displays before allowing their opponents to control the game after the interval.
Typhoon Hagibis wreaking World Cup havoc
Hagibis, which is on course to hit Tokyo and Yokohama, looked to be heading towards Fukuoka earlier this week before its path shifted, allowing the build-up to the Ireland v Samoa game to proceed as normal.
World Rugby will make a decision on whether or not Scotland v Japan will go ahead on Sunday morning.
In the event of a cancelled match both sides would be awarded two points, which would ensure that Japan finish as group winners.
Despite the uncertainty, Ireland number eight CJ Stander insisted the squad have not been distracted by the weather concerns.
"We know that our game is going ahead. All we can do is concentrate on that now," said the South Africa-born back row.
"You can't look at other stuff that's out of our control."
The question marks over the playing surface in Fukuoka, which was closely scrutinised by Schmidt and his staff during Friday's captain's run, have added another dimension to the build-up.
But Ireland's players and coaches have remained at pains to point out that although the focus of many onlookers has been elsewhere, their priorities have not changed.
"We need to win our game," said scrum coach Greg Feek.
"To be involved in a World Cup is an honour and it's so exciting to be part of it.
"You just don't want those distractions for all of us to forget about how special the tournament is."
The teams
Ireland: Larmour; Earls, Henshaw, Aki, Stockdale; Sexton, Murray; Healy, Best, Furlong, Henderson, James Ryan; Beirne, Van der Flier, Stander.
Replacements: Scannell, Kilcoyne, Porter, Kleyn, O'Mahony, McGrath, Carbery, Conway.
Samoa: Nanai-Williams; Tuala, Leiua, Taefu, Fidow; Seuteni, Polataivao; Mulipola, S Lam Alaalatoa, Paulo, Le'aupepe; Vui, Ioane, J Lam.
Replacements: Niuia, Alo-Emile, Lay, Fa'asalele, Tyrell, Cowley, Pisi, Fonotia.
What they said
Ireland coach Joe Schmidt: "We've just got to make sure our game gets finished with the right result for us.
"We need to get out and get a result. It's a situation nobody wanted to have."
Samoa coach Steve Jackson: "What better opportunity to finish the World Cup?
"Knowing that we're on an airplane on Monday, going home, to have a scalp like that would be great."
Match stats
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