Barring a huge upset, Canada and the U.S. are expected to face off in Sunday's final to decide who goes to the 2016 Games in Rio de Janeiro. The loser will have one last chance to qualify, via a world repechage tournament.
The U.S. men finished sixth on the HSBC Sevens World Series while the Canadians were ninth. The Americans won four out of five meetings between the two this season.
"It's a good squad," said Middleton. "It's the best we can assemble at this point."
Ardron, a back-row forward who is captain of the national 15-man team, and winger Hassler both play for Welsh club side the Ospreys. Hassler, named to the Pro12 team of the year in 2013-14, missed the start of last season with a knee injury suffered on international duty with Canada against Romania last November.
Paris, a speedy winger, recently helped Agen win promotion to France's elite Top 14. He scored a sensational 105-metre try in the semifinals of the playoffs.
Braid, a back who plays for the Glasgow Warriors, was part of Middleton's squad in London — the last stop of the sevens tour — as an emergency injury replacement.
"We called in four guys who showed a lot of interest in being a part of the Olympic pathway," Middleton said from Victoria, prior to boarding a plane to the U.S. "So they came in. They weren't dead certs for selection but they certainly came through in training, showed that little bit of quality."
Injuries also opened the door with Liam Underwood and Sean White both unavailable. Others, like Admir Cejvanovic and Lucas Hammond, contested for a position but missed out.
Phil Mack, an influential member of the squad, returns from a knee injury.
The Canadian men have been placed in a pool with the Bahamas, Cayman Islands, Guyana and Trinidad and Tobago. The other group at features the U.S., Barbados, Jamaica, Mexico and St. Vincent.
The winner of the North America Caribbean Rugby Association (NACRA) Sevens Championships joins host Brazil and Fiji, South Africa, New Zealand and England — the top four teams from the recently completed Sevens World Series season — at the Rio Games.
The other six Olympic teams will come from five regional tournaments plus the repechage competition.
On the women's side, Canada has already qualified for Rio by virtue of its second-place finish in the Women's Sevens Series.
The U.S., which was fifth in the standings, is expected to roll through the NACRA women's field which also includes the Bahamas, Barbados, Cayman Islands, Guyana, Jamaica, Mexico and Trinidad and Tobago.
John Moonlight (capt.), Conor Trainor, Adam Zaruba, Phil Mack, Harry Jones, Ciaran Hearn, Sean Duke, Justin Douglas, Tyler Ardron, Mike Fualiefau, Connor Braid, Nate Hirayama, Jeff Hassler, Taylor Paris.
Coach: Liam Middleton
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