The squad includes debutants, Guyanese batsman Leon Johnson and Australia-born all-rounder Brendan Nash.
Barbadian fast bowler Kemar Roach has been included for his first full tour, while Jamaican wicketkeeper Carlton Baugh returns to West Indies colours after almost two years in the wilderness.
All-rounder Dwayne Bravo has not been considered for selection for either tour because of an injured ankle.
Prolific left-hander Shiv Chanderpaul has not been included for the Tri-Nation series in Canada but will join the team for the Champions Trophy.
The Tri-Nation series is carded for August 16-25 in Toronto with the Champions Trophy scheduled for September 12-28.
Team: Chris Gayle (captain), Ramnaresh Sarwan, Sewnarine Chattergoon, Shiv Chanderpaul, Xavier Marshall, Shawn Findlay, Leon Johnson, Brendan Nash, Carlton Baugh, Dave Mohammed, Nikita Miller, Kemar Roach, Fidel Edwards, Daren Powell, Jerome Taylor.