It was supposed to be the summer Canada's top basketball talent finally stepped up to the plate, when the toughest task for the team's staff would have been selecting a squad from the deepest talent pool in history.

That task might have meant cutting an NBA player. It would have been a good problem to have.

But as the Canadian men's team tipped off its pre-FIBA World Cup training camp on Monday morning, the talk — again — was more about who wasn't there than who was.

Along with Andrew Wiggins of the Minnesota Timberwolves, who already was ruled out, several other prominent Canadian players won't play for Canada, including Denver guard Jamal Murray, New York Knicks rookie RJ Barrett, Cleveland's Tristan Thompson, Dwight Powell of the Dallas Mavericks, Shai Gilgeous-Alexander of Oklahoma City, and Nickeil Alexander-Walker of the New Orleans Pelicans.

"Obviously, we would love to have every single person here and put the best roster we could, but sometimes the group of guys you put out there, you need the sum of the whole to be greater than its parts," said Miami Heat centre Kelly Olynyk. "Anybody who wanted to come, we'd gladly have them, but we've gotta rock with who's here."

Olynyk, Joseph mainstays

Barrett pulled out with a calf strain, while Murray said he injured his ankle a couple of days ago. Both are at camp but won't travel with the team. Memphis Grizzlies swingman Dillon Brooks, whose NBA season was cut short by a foot injury, was also at camp Monday but not participating.

Olynyk and Sacramento guard Cory Joseph have become mainstays of the national program. The 27-year-old Joseph has given up a good chunk of every summer since he was 15 to pull on the Canadian jersey.

Why?

"Just the guys, the guys that I grew up with who are from the same places I'm from, who can relate to how I grew up, I think those memories and stories that we build on the road makes it fun playing basketball with all of them," Joseph said.

Olynyk and Joseph headline a 19-player roster that includes NBAers Khem Birch (Orlando Magic), Chris Boucher (Toronto Raptors), and Oshae Brissett (Raptors). Canada's original camp invitation included 29 players.

Day 1 for coach Nurse

The Canadians will host Nigeria in exhibition games on Wednesday in Toronto and Friday in Winnipeg before flying to Australia for a series of friendlies.

I'm exhilarated to have this opportunity ... and judging by the first practice, it's a helluva group of guys, so I'm excited. — Canada head coach Nick Nurse

Expectations for this team were sky-high heading into arguably the program's most important summer in history. The Canadian men's team, which hasn't made an Olympic appearance since 2000, can clinch a berth in the 2020 Tokyo Games with a top-seven finish at the World Cup. Failing that, they face playing a last-chance tournament next summer that would require another big commitment from players, with no Olympic guarantee.

Monday also marked Day 1 for Nick Nurse, who takes over as head coach of Canada's national team just weeks after leading the Raptors to their first NBA title.

Asked about key absentees, Nurse said: "My thoughts are I'm super proud of the guys that are here and super excited to coach them.

"You can't force anybody to play, it's a unique situation, everybody understands the uniqueness of it. I'm exhilarated to have this opportunity and coach these guys and judging by the first practice, it's a helluva group of guys so I'm excited."

No. 23-ranked Canada is in a tough Group H at the World Cup that includes No. 6 Lithuania, 11th-ranked Australia and 37th-ranked Senegal. The Canadians tip off the World Cup in China on Sept. 1 versus Australia.

'Our focus is on who is here'

Rowan Barrett, the team's general manager, said getting all of Canada's to players to commit was always going to be a tough task.

"I think you can see all across the world that this was a challenging thing. We managed the best that we could. We're consistent in our approach, which is we need to build a big and strong pool understanding that each summer we're going to miss players," he said. "Sometimes it's injuries. Sometimes it's something in their life. It could be a trade. It could be a contract. Something can come up.

"Our focus is on who is here. We have players who just got married (Thomas Scrubb was married on Saturday) who are here. No honeymoon or the honeymoon is going to be in Australia with a 10-foot rim, a ball and a bunch of his brothers. We'e going to focus on that."

Canada used a revolving doors of three dozen players in a convoluted World Cup qualifying process stretched over almost two years. Canada Basketball estimated the players covered 2.3 million kilometres combined in travel. The Canadians clinched a World Cup berth in December with a thrilling win over Brazil in Brazil.

The buzz since then had been about who would play for Canada, which saw more success on the NBA stage this past season than ever before. That lofty balloon seemed to lose some of its air on Monday.

Murray, however, believes this Canadian team will still get the job done in China.

"I have a lot of faith in my young guys. That's why they're here, the reason they're here, to prove themselves, go out and show the world, not just this city, not just this country, the world what they can do," Murray said. "So, it was a big plan for me to come here and help them, lead them, show the world what we can do next year in the Olympics.

"I have a lot of faith in these guys, I have no doubt they're going to go out there and make Canada proud."

Training camp invitees

Canada's training camp invitees are as follows:

RJ Barrett, Guard, Mississauga, Ont. (New York Knicks).

Aaron Best, Guard, Scarborough, Ont. (Riesen Ludwigsburg — Germany).

Khem Birch, Centre, Montreal (Orlando Magic).

Chris Boucher, Centre, Montreal (Toronto Raptors).

Oshae Brissett, Forward, Mississauga, Ont. (Toronto Raptors).

Melvin Ejim, Forward, Toronto (BC UNICS — Russia).

Brady Heslip, Guard, Burlington, Ont. (Istanbul BBSK — Turkey).

Cory Joseph, Guard, Toronto (Sacramento Kings).

Kaza Kajami-Keane, Guard, Ajax, Ont. (Mitteldeutscher BC — Germany)

Jamal Murray, Guard, Kitchener, Ont. (Denver Nuggets).

Andrew Nembhard, Guard, Aurora, Ont. (Florida Gators — NCAA).

Duane Notice, Guard, Woodbridge, Ont. (Raptors 905 — G League).

Kelly Olynyk, Forward, Kamloops, B.C. (Miami Heat).

Eugene Omoruyi, Forward, Rexdale, Ont. (Oregon Ducks — NCAA).

Kevin Pangos, Guard, Newmarket, Ont. (FC Barcelona Basketball — Spain).

Addison Patterson, Guard, Milton, Ont. (Bella Vista Prep — Arizona)

Phil Scrubb, Guard, Richmond, B.C. (Zenit Saint Petersburg — Russia).

Thomas Scrubb, Forward, Richmond, B.C. (Openjobmetis Varese — Italy).

Kyle Wiltjer, Forward, Portland, Ore. (Unicaja Malaga — Spain).

Players listed in italics will participate in training camp but won't play at World Cup.