Argentina and the U.S. are the seeded teams in the men's field by virtue of their finish in the HSBC World Series standings this season. The Americans were sixth overall while Argentina was eighth, one place ahead of Canada.
Canada defeated Argentina 26-24 in the Pan Am final in Guadalajara four years ago.
The Pan Am rugby sevens competition is scheduled for July 11-12 at BMO Field .
Canada and Argentina are joined in Group B by Brazil and Guyana. Pool A features the U.S., Uruguay, Chile and Mexico.
The winner of each pool will play the lowest-rank team in the other group while No. 2 takes on No. 3 in the cross-pool knockout stages.
Canada, which opens against Guyana, will face Argentina in the final match of Day 1 in a game that will likely decide the pool winner.
First up for the Canadian men is a North American Olympic qualifier this weekend in Cary, N.C., where they are expected to face the U.S. in the final to see who goes to Rio de Janeiro. The loser has one more chance to qualify, via a world repechage tournament.
The Canadian women are seeded first in their Pan Am competition, which marks the debut of women's rugby sevens at the Games. They are followed by the U.S., Brazil, Argentina, Colombia and Mexico in the seeding with all teams to play each other in a round-robin.
The gold- and bronze-medal matches will be determined by the finish after pool play.
Canada will open against Colombia and close pool play against its toughest rival, the U.S.
The Canadian women have already qualified for the 2016 Games in Rio by virtue of their second-place finish in the Women's World Series.