Before the pair caught the flight with assistant coach Leon Birnie, of Napier, they had received their shirts from family members at a ceremony at the Ellerslie AFC's Michaels Avenue Reserve last Sunday.
Morton's brother, Harry, 18, a Bay youth squad member, had the honour.
For Arquette, mum Yuko had the pleasure although father Chase, an ex-Havelock North women's coach, also drove up for the momentous occasion.
Whether the pair will run on to the pitch for the Jitka Klimkova-coached squad of 21 in the three-week tourney that ends on April 5 remains to be seen, but nothing will compare with the moment when they will grapple with pre-match nerves and pride to the tune of God Defend New Zealand in their group C encounters involving Paraguay, Spain and Arquette's mother's birth country of Japan.
Morton, a fifth-former at Hastings Girls' High School, didn't have much time to do research on Costa Rica but was aware it's in the South American continent.
"All I basically know is that it's a 19-hour flight and I hooked up to where we're staying but not much else."
She wouldn't have known that it's the first U17 women's tournament to be staged in South America for the 16 nations in its fourth edition.
The Fifa World Cup kicks off tomorrow with the hosts among the countries playing in the first four games of the tourney.
"It'll be a great opportunity and experience. It's always been a dream," says the daughter of Hanna Cotter and Steve Morton, of Tikokino, before their match kicks off at Tibas, about 4km north of the capital city.
"From the time I was probably 5 years old, I wouldn't play any other sport but soccer. I never liked any other sport," she says, adding her parents have been a great help.
"They [parents] said make our country proud. They said go strong and never give up."
The school is also buzzing, wishing Morton all the best and a fun-filled trip.
"I'll be nervous but once we kick off I'll be more relaxed."
The leftback/winger is banking on game time because of her versatility but wants to "stay strong on the ball" after some poor team results on a pre-tourney tour to the United States last month.
The Maycenvale Misfits midfield/striker will return home unsure which club to play for amid speculation the Hastings club won't field a team in the women's division one this winter.
But Morton has other challenges to endure before that.
With powerhouses such as Japan, inaugural champions North Korea, Germany, China, Canada and Nigeria in the four-pool tourney, the pair are under no illusions how difficult their tasks will be.
Therein lies the enormity of the task and outside the glitz and glamour the burden of carrying a nation's expectations.
The Kiwi World Cup tournament in 2008 stoked Arquette's desire to foot it on the international stage from the age of 10.
She recalls watching the New Zealand versus Denmark game live with her father at the Cake Tin in Wellington, which the Kiwis lost 2-1.
They beat Colombia 3-1 but failed to make the cut for the last eight in the knockout phase.
"I saw two other games between North Korea and different countries, too," said the Havelock North High School pupil.
Selectors scouted Arquette's talent early and she was in a homestay situation with another gifted player, Kaisa Tsuruta, of Nelson, in Christchurch, while representing Halswell United from the age of 14.
"It took a lot of hard work and effort," she revealed.
A promising piano and dancing stint, which her mother inspired, was shelved.
"I wasn't flexible enough in dancing so I let it go," she said with a laugh. "I don't take piano lessons but I still play it."
The defensive midfielder, akin to Morton, will use the tourney to gauge what it takes to become a professional footballer in her desire to graduate to the ranks of a fully fledged Football Fern.
In an email to Hawke's Bay Today yesterday, Birnie lauded the hosts and Fifa for having done "a fantastic job".
"Everything the girls have been involved in has been very professional.
"We are staying at the Barcelo, which is a lovely complex, nice spacious rooms, gym, lovely outdoor area with pool which the girls have been using for recovery sessions."
He said the food was delicious but appropriate for athletes. Refrigerated bottled water and sports drinks were also accessible.
"Today [yesterday] they had Fifa delegates check player identification and then present them with their official certificate of attendance, memorabilia and player photo," Birnie said of the Kiwis who are staying at the same complex as Japan, Spain and Paraguay.
"Although we are staying at the same complex we don't cross paths as every team has their own food hall, meeting room and floor they sleep on."
Birnie said the players were lapping up Costa Rica, their treatment as "professionals" and every other aspect of what a soccer world cup offered.
"They are very excited and can't wait for the first game against Paraguay [at the Ricardo Saprissa Ayma Stadium]. They just want to get out there to play.
"We are not sure how many spectators to expect but we've just heard that Costa Rica's first game is sold out with 30,000 fans expected to watch it," he said of the game kicking off at 8pm (Costa Rican time) at the Nacional Stadium. Birnie said the plan was to expose the pair to Central Football's coaching structure when they returned from the cup.
"They can be role models for other younger players during the girls' holiday programmes," said the 31-year-old, who is also a Central Football administrator in Napier.