Ireland forwards coach Simon Easterby has praised the competition levels within the squad ahead of their final Pool A fixture on Saturday.
In need of a victory to ensure qualification to the quarter-finals, Ireland are expected to name a strong side to take on Samoa in Fukuoka.
“You want to come to a World Cup with 31 players who are all challenging for starting spots,” said Easterby.
“If they don’t get in the starting team there is a bit of disappointment.
“There is an edge and there is a bit of ‘I’ll show you I can be the one’.”
Earlier this week defence coach Andy Farrell indicated that Ireland were now into the “business end” of their tournament, adding that they would be selecting their strongest available side against Samoa.
With Jordi Murphy set to recover in time for the weekend, Ireland’s coaches will be able to select their starting side from a fully-fit 31-man squad.
Of Ireland’s forwards, only Sean Cronin and Andrew Porter are yet to start a match during the tournament, while only flanker Peter O’Mahony has started all three.
“In this group there is a good competitive nature,” Easterby said.
“The scrum session [during Tuesday’s training] was tasty.
“There was a little bit going on in there and that’s good, that’s what you want. You need those sessions and you need that competitive edge.”
While any win secures Ireland a top-two finish in Pool A, even a bonus-point win would not guarantee them top spot.
They will not know their fate until Sunday when Japan face Scotland in Yokohama, and if the hosts win or collect two losing bonus points they will advance as group winners.