Veterans Christine Sinclair, Erin McLeod and Diana Matheson lead a veteran core augmented by five teenagers in John Herdman's training camp roster ahead of next month's Rio Olympic qualifying tournament in Texas.

Herdman has called in 23 women for the soccer camp, which opens Saturday in Vancouver. He will have to cut that down to 20 for the CONCACAF qualifier, and 18 for the Games this summer should they qualify as expected.

"There will be some tough decisions," Herdman said Friday in a statement.

"This is really a critical phase in our preparations," he added. "We had time together in November and December, so we have a strong sense of what these players can do. This camp will be about organization, firming up the connection between players, and striking the right balance on the pitch."

The Canadian women have qualified for the last two Olympics, winning bronze in 2012 and reaching the quarter-finals in 2008.

Team has strong core of experience

Of the 23 in camp, 14 are veterans of the World Cup team that exited in the quarter-finals last summer.

While six players are 30 or older (Sinclair, McLeod, Matheson, Marie-Eve Nault, Melissa Tancredi and Rhian Wilkinson), there are 12 who are 23 or younger, with Herdman making good on his promise to introduce new talent after a largely disappointing performance on home soil at the World Cup.

Backup goalkeeper Karina LeBlanc has retired but there is no place for Lauren Sesselmann, Carmelina Moscato, Kaylyn Kyle, Jonelle Foligno and Adriana Leon among others.

The teen contingent includes 17-year-old Jessie Fleming, who played at the World Cup, as well as 16-year-olds Kennedy Faulknor and Deanne Rose, 17-year-old Gabrielle Carle, and 18-year-old Marie Levasseur.

There is more youth in 20-year-olds Kadeisha Buchanan, Ashley Lawrence, Rebecca Quinn and Nichelle Prince, 21-year-old Janine Beckie, 22-year-old Sabrina D'Angelo, and 23-year-old Shelina Zadorsky.

Buchanan, a rising world star, and Lawrence were both key players at the World Cup.

"We have a leader in Sinclair who really inspires the younger players, we have a group of experienced international stars, and a crop of young, hungry players," Herdman said. "I'm eager to see how they come together over the next month."

Canada's final roster for the Olympic qualifier is expected the final week of January.

Rounding out the camp roster is Stephanie Labbe, Josee Belanger, Allysha Chapman, Sophie Schmidt and Desiree Scott.

Canada to face Guyana first

Canada, ranked 11th in the world, is in Group B with No. 48 Trinidad and Tobago, No. 76 Guatemala and No. 79 Guyana.

The Canadians will play all their games in Houston's BBVA Compass Stadium. They open pool play Feb. 11 against Guyana before facing Trinidad and Tobago on Feb. 14 and Guatemala on Feb. 16.

The top-ranked Americans head up Group A in Frisco, Texas, along with No. 26 Mexico, No. 34 Costa Rica and No. 108 Puerto Rico.

The top two teams in each group advance to the Feb. 19 semifinals in Houston with the two winners qualifying for the Olympics. The championship game goes Feb. 21.

Brazil, Colombia, France and Germany have already qualified for Rio. They will be joined by two teams from Africa, two from Asia, either Papua New Guinea or New Zealand from Oceania plus one more European team from the Netherlands, Norway, Sweden or Switzerland.