John Tait called choosing his 12-woman roster for the Rio Olympics the most challenging time of his coaching career.

Tait whittled his rugby sevens squad down to 16 before telling four of those that they would serve as alternates.

"While there were 12 really great conversations, getting to tell the athletes they're realizing their (Olympic) dream, there were four really extremely difficult ones and painful ones too," Tait told a media conference call Friday.

The pre-Games stress will have been worth it if the Canadian women can deliver on their medal favourite status a month from now when the sport makes its Olympic debut.

Tait says his team, third in the World Series standings this season and second last season, is ready for the spotlight.

"We've never been faster, stronger and more technically ready that we have for the Olympics," the towering former Canadian international forward said in praising his support staff and athletes.

Health issues aside, the names of stalwarts like captain Jen Kish, Ghislaine Landry, Ashley Steacy, Kelly Russell, Bianca Farella, Karen Paquin and Britt Benn were probably pencilled in months ago.

But Tait still faced a perfect storm in selection this season. Veteran players went down to injury — three in one scrimmage — forcing him to dig deep into his roster. Youngsters like 19-year-old Charity Williams and 20-year-old Hannah Darling, previously identified as hopefuls for the 2020 Olympics, stepped up.

Tait, who has 20 to 24 players centralized in Victoria, used more than 20 players on the five-stop World Series. And when veterans like Steacy, Elissa Alarie, Natasha Watcham-Roy and Magali Harvey returned from injury late in the season, the Canadian coach had decisions to make.

Steacy, a veteran who anchors the Canadian defence, and Watcham-Roy made the roster.

But Harvey and Alarie, along with Julia Greenshields and Sara Kaljuvee, were named alternates. Two of those will travel with the team to a training camp north of Toronto later this month and one will travel with the team to Brazil.

Teams can replace an injured player the first two days of the three-day Olympic competition.

Harvey's omission drew plenty of attention Friday.

The Quebec City native was named World Rugby's Player of the year in 2014 in 15s play after starring at the Women's World Cup. But her sevens career has been more up and down.

Tait had used the speedster primarily as an impact player off the bench although she can also cover at sweeper and kicker.

"I'm well aware of what she's capable of," said Tait, who has selected her in both Canadian sevens and 15s teams.

Harvey's cause was not helped by an ankle injury that forced her to miss three World Series events this season. Steacy's return from injury moved Landry from sweeper to elsewhere in the backs, shifting other players down the backline.

The emergence of Williams, who can provide cover in both the forwards and backs, and the form of Benn also moved Harvey down the pecking order.

Tait says nine of his players are good enough to start and finish games, with the remaining three offering cover coming off the bench.

In Rio, third-seeded Canada opens pool play in a group with No. 4 Britain, No. 9 Brazil and No. 10 Japan.

The Canadian women won the last stop on the 2015-16 HSBC World Sevens Series, toppling Series leader Australia 29-19 in France. The Australians won the first three stops this season.

"Australia had a great run this year but hopefully we put some doubt in their mind in France," said Tait. "They are beatable, for certain. We've done it before. We plan to do it again."

New Zealand is seeded second at the Games.

Canada's roster includes nine members of the team that won gold at the 2015 Pan-Am Games: Kish, Landry, Steacy, Darling, Benn, Paquin, Russell, Watcham-Roy and Kayla Moleschi.

Seven of the players were on the team that won silver at the 2013 Rugby World Cup Sevens in Moscow.

"There's a lot of experience in the side ... The group we have provides us with the best of what we need out there in terms of winning possession, retaining possession, turning possession into scores as quickly as possible. And most importantly staying in our defence and attack structures on the biggest stage under the most pressure," Tait said.

The team was unveiled Friday at a news conference in Victoria where the players were presented with their Canadian team jackets.

"Honestly to have the opportunity to lead these beautiful and wonderful women into the Rio Game ... is a huge honour and privilege," Kish said.

"We're a squad of sisters and I think when we step out on that field, that's what you're going to see — is the sisterhood. I'm just so proud of these girls."

The Canadian women will train in Victoria before heading to the Toronto-area camp on July 23. The team flies to Rio on July 28 with Olympic play starting Aug. 6.

Canada Rugby Sevens Olympic Roster

Britt Benn, Guelph Redcoats, Napanee, Ont.; Hannah Darling, Peterborough Pagans, Warsaw, Ont.; Bianca Farella, Town of Mont Royal RFC, Montreal; Jen Kish (capt.), Edmonton Rockers, Edmonton; Ghislaine Landry, Toronto Scottish, Toronto; Megan Lukan, unattached, Barrie, Ont.; Kayla Moleschi, Williams Lake Rustlers, Williams Lake, B.C.; Karen Paquin, Club de Rugby Quebec, Quebec City; Kelly Russell, Toronto Nomads, Bolton, Ont.; Ashley Steacy, Lethbridge, Alta.; Natasha Watcham-Roy, Hull Volant, Gatineau, Que.; Charity Williams, Markham Irish, Toronto.

Follow @NeilMDavidson on Twitter