Ireland's record-points scorer David Humphreys - set for his first international start in 13 months - is treating his 65th cap against the United States on Saturday as if it were his last.
All seven replacements in last weekend's historic 17-12 defeat of South Africa at Lansdowne Road have earned a recall to coach Eddie O'Sullivan's starting line-up and Humphreys, 33, is one of many with a point to prove.
Munster's Frankie Sheahan - without a start in two years - Marcus Horan and Donncha O'Callaghan, Leinster duo Guy Easterby and Eric Miller and 65-cap veteran Kevin Maggs, now of Ulster, all earn rare starts along with Humphreys, with O'Sullivan insisting: "The team for Argentina isn't picked yet."
"There are guys who are coming into the team now who are chomping at the bit. Maybe they haven't had a lot of Test rugby or have been coming off the bench."
Ireland face Argentina in Dublin on Saturday week - coincidentally the same opposition as when Humphreys last started for Ireland during last year's World Cup.
O'Sullivan added: "These fellas have a point to prove - South Africa is done and dusted, it was a great performance but it's yesterday's news now. We raised our standards against the Springboks and the trick now is to maintain them. That's the benchmark."
Humphreys, who will break through the 500-point barrier against the Americans with a nine-point haul, said: "We've got to get the focus right on the day. The US may be classed as weaker opposition, but we'll treat them with the respect they deserve.
"Every international game could be my last one, so that's the way I look at it. I'll enjoy it by playing well and winning. My first priority is always to go out, play well and enjoy it, and try to bring the best out of the younger players who have a huge opportunity on Saturday."
Both Humphreys' Ulster colleague Tommy Bowe and Munster flanker Denis Leamy will make their senior debuts against the 16th-ranked Eagles, and 20-year-old Bowe will be hoping to replicate a hero of his youth.
"The first time I was at Lansdowne Road, it was about 10 years ago in the schoolboy terrace," he admitted.
"My dad had a 10-year ticket and Ireland beat England. Simon Geoghegan was an old favourite of mine - when I was young everyone wanted to be him. Maybe in a few years they'll all want to be me!"
Leamy, at 22 one of Ireland's rising back-row stars, may just be in his first full season with Munster - but will be surrounded by familiar faces on Saturday.
"I've been very happy with my form with Munster," said the converted openside, who claimed a try in the province's 15-9 Heineken Cup defeat of Harlequins last month.
"To make my international debut with the Munster front five will be a special moment for me - just being with the Ireland squad is great."
O'Sullivan, who admittedly spent three great seasons as a technical director to the Eagles, knows a repeat of 2000's record 83-3 victory over the States is not on the agenda.
"I know Tom (Billups) and he'll have them very organised. They'll certainly test us - they ran five tries past the French in the summer, so we won't take them for granted."
Billups has made four changes, one positional, to the side that lost 39-31 to France in Connecticut in July, with lock Alec Parker, blindside flanker Brian Surgener and right wing Al Lakomskis returning, with captain Kort Schubert of the Cardiff Blues shifting to number eight.
