Jobs will be on the line at Sam Boyd Stadium, says coach Geraint John.
"Some of these (new) players want to know why they're not getting more opportunities," John said. "Well here's the chance for them."
Unavailable due to injury are Sean Duke, Mike Fuailefau, Lucas Hammond, Ciaran Hearn, Nathan Hirayama, Adam Kleeberger and Pat Parfrey.
John Moonlight will captain the squad in the absence of Hirayama.
John has yet to name his roster for the Feb. 7-8 event in New Zealand that follows Las Vegas. Some of his injured players will be ready by then while some of the newcomers can stake their claim to stay this weekend.
Adding some urgency to the matter is Canada's somewhat unfortunate start to the season.
The Canadians finished runners-up in the consolation Bowl competition in the October season opener in Australia, which was good for 10th in the 16-team event (each sevens event sees the four best teams at the competition go after the Cup while the other teams compete for the Plate, Bowl and Shield depending on their performance in the round-robin).
Canada lost in the Bowl semifinal in Dubai in late November and was beaten in the Shield final in South Africa in early December, with some players perhaps fatigued from their part in a six-week, six-country stint with the national 15-man squad.
As a result, Canada stands 13th in the HSBC Sevens World Series standings as it prepares for games against No. 2 South Africa, No. 7 Kenya and No. 9 Wales in Pool A in Las Vegas.
"We're all capable of beating each other in this pool " said John. "It's going to be very very tight."
Canada opens play Friday at the three-day event with games against Kenya and South Africa.
John calls it perhaps the most physical of the four groups. And he knows there is nowhere to hide at Sam Boyd Stadium, which is just 58 metres wide as compared to the normal 70.
The Canadian coaches are putting a premium on defence after a disappointing showing last time out in Port Elizabeth.
The team goal is completing more than 80 per cent of tackles, which it accomplished in Australia. But the number fell to 74 per cent in Dubai and 61 per cent in South Africa.
South Africa won the Las Vegas event last year with a tackle rate of more than 90 per cent.
One of the new Canadian faces is Jordan Wilson-Ross, who has returned to the rugby fold after playing football. And Sean White, who has made 24 appearances for Canada's 15-man team, returns to the sevens side for the first time since 2012.
The Canadians will return to Victoria after the Vegas event before leaving for New Zealand at the end of next week.
Rugby Canada also has a young Maple Leafs side competing at a companion tournament in Las Vegas.
Connor Braid, James Bay AA, Victoria; Nanyak Dala, Castaway Wanderers, Saskatoon; Justin Douglas, Abbotsford RFC, Abbotsford, B.C.; Sean Ferguson, UBC Thunderbird, Vancouver; Harry Jones, Capilano RFC, North Vancouver; Phil Mack, James Bay AA, Victoria; Duncan Maguire, St. Albert Rugby Club, St. Albert, Alta.; John Moonlight, James Bay AA, Pickering, Ont.; Mike Scholz, Castaway Wanderers, Oakville, Ont.; Conor Trainor, UBC Old Boys, Vancouver; Sean White, James Bay AA, Victoria; Jordan Wilson-Ross, James Bay AA, Alliston, Ont.