Chris Henry insists Ireland's training has taken on a combative edge as they approach yet another critical showdown with Argentina.
Victory at Aviva Stadium on Saturday will secure the winners a place in the top eight of the IRB rankings, which are being used to determine the seedlings for the 2015 World Cup.
The losers will slip into the third tier of seeds for next month's draw and face the possibility of being selected in a pool containing two major nations.
If that prospect alone is insufficient to inspire Ireland, flanker Henry believes the anguish of their 16-12 defeat by South Africa in the Guinness Series opener should spur them on.
"The atmosphere's boiling up. Losing two weeks ago was one of the hardest moments I've had to face in my rugby career," the Ulster openside said.
"Losing at home, it was hard to take. I didn't think it would hurt as much, but it did.
"Everyone put everything into South Africa and that was disappointing, but we're not far off.
"It's been bubbling this week. Not everyone trained on Monday, but it definitely started to bubble yesterday. That was the edgiest training session of this campaign.
"In teams I've been involved in before, if you're edgy at this stage of the week and you're getting tetchy with your team-mates, then that's a good sign.
"Last Saturday's win against Fiji wasn't a Test, but it was still great to score tries and enjoy rugby again.
"If we can get the balance of that enjoyment and the hurt of South Africa, we'll be in a good place.
"As players we're not stupid, we know what's at stake on Saturday, but for me it's about Ireland playing at home," - Chris Henry.
"As players we're not stupid, we know what's at stake on Saturday, but for me it's about Ireland playing at home.
"We don't want to lose at Aviva Stadium again and that's what we're holding on to."
Henry, who will win his fourth cap on Saturday, accepts that a productively fractious week of preparation is meaningless if they fail to reproduce the fireworks on match day.
"There's a bite there with people fighting for places," he said.
"But you can do all the training you want, it's bringing that physicality and aggression into the game that matters.
"You need to have that adrenalin pumping come kick-off and not leave it on the training field."
Coach Declan Kidney, whose position will come under intense scrutiny should Ireland lose, names his team to face Argentina at lunchtime tomorrow.
Given his conservatism and the importance of the match, he is expected to revert to the XV who were edged by South Africa in a highly-winnable Test.
The only change is likely to be uncapped 21-year-old Ulster winger Craig Gilroy, who scored a hat-trick in Saturday's 53-0 win over Fiji, replacing Andrew Trimble.
"Some lads are getting the opportunity at a young age and that's great, it's exactly what we want to see," Henry said.
"We want to see younger guys getting a go and if they're ready, they're ready.
"Obviously it's a huge step up but when a younger players comes in and adds enthusiasm, it drives other players on.
"Donncha O'Callaghan talks about it, he likes the atmosphere around the younger lads."