The Pakistan Cricket Board (PCB) had earlier refused permission for fast bowler Naseem Shah to play in The Hundred competition in England.
"After taking into consideration Pakistan's busy and packed cricket calendar... and following consultations with the three players as well as the national selection committee, it has been decided to decline their requests," the PCB said in a statement late on Friday.
"The three are all-format cricketers and their services are expected to be required in the upcoming eight months during which Pakistan will play nine Tests, 14 ODIs, and nine T20Is.
"As such, and in line with the PCB's workload management policy, it is in the best interest of Pakistan cricket and the players that they skip the upcoming event in Canada so that they are in their best mental and physical shape for the season."
Pakistan begin their home season next month with a two-Test series in Bangladesh.
Asif Ali, Iftikhar Ahmed, Mohammad Amir and Mohammad Nawaz - all predominantly limited-overs players - have been cleared for the Global T20, which begins next week.
