The tourists will now have to pick replacements from their large touring squad against an in-form Pakistan playing in familiar conditions.
Babar Azam's team followed their semi-final showing at the Twenty20I World Cup with a 3-0 rout of Bangladesh in an away series last month.
"We want to carry the momentum and the confidence that we have gained during the World Cup and the tour of Bangladesh," Babar said.
"There has always been talk that they are missing some key players but all those who are here are of international standard so we will not take them easy."
Pakistan have beaten the West Indies in 12 of their 18 T20I clashes, suffering three losses and as many no results.
Babar has formed an unbreakable opening partnership with Mohammad Rizwan and a solid batting line-up alongside a bowling attack led by the pace of Shaheen Shah Afridi has seen the team win eight of their last nine T20Is.
Rizwan is the first batsmen ever to score 1,000 T20I runs in a calendar year, amassing 1,123 in 26 matches, while Babar has scored 853 in the same number of games.
The West Indies have had contrasting fortunes, failing to qualify for the World Cup semi-final after winning the competition in 2012 and 2016.
"We know what happened in the World Cup and we're not going to go back there," head coach Phil Simmons said.
"We are looking to move forward and we now want to move forward."
'Appreciate the West Indies'
Pakistan hope the series will help them convince other teams to visit after New Zealand abandoned a tour due to a security alert in September.
The cancellation was followed by England withdrawing their men's and women's teams from a series scheduled for October.
"It was important to have this series and we must appreciate the West Indies team for coming here because there were fears about whether teams will come or not," said Babar.
"I am sure with 100 per cent crowds allowed we will have entertaining cricket."
Monday's game will be followed by T20Is on Tuesday and Thursday and by three one-day internationals on Saturday, Monday and Wednesday -- all in Karachi.
Pakistan: Babar Azam (captain), Shadab Khan, Asif Ali, Fakhar Zaman, Haider Ali, Haris Rauf, Iftikhar Ahmed, Khushdil Shah, Mohammad Hasnain, Mohammad Nawaz, Mohammad Rizwan, Mohammad Wasim Jr, Shaheen Shah Afridi, Shahnawaz Dahani, Usman Qadir
West Indies: Nicholas Pooran (captain), Shai Hope (vice-captain), Darren Bravo, Dominic Drakes, Akeal Hosein, Brandon King, Gudakesh Motie, Romario Shepherd, Odean Smith, Oshane Thomas, Hayden Walsh Jr, Rovman Powell