Pakistan, who have an unbeatable 2-0 lead in the series, handed an ODI debut to 23-year-old fast bowler Shahnawaz Dahani, who came into the side in place of Haris Rauf.
Hasan Ali returned to the side, giving fast bowler Shaheen Shah Afridi a rest.
West Indies made three changes, as they left out Alzarri Joseph, Anderson Phillip and Brandon King to bring in Keacy Carty, Jayden Seales and Keemo Paul.
Pakistan won the first match by five wickets and the second by 120 runs – both in Multan.
Pakistan: Babar Azam (capt), Fakhar Zaman, Imam-ul-Haq, Mohammad Haris, Mohammad Rizwan, Khushdil Shah, Mohammad Nawaz, Shadab Khan, Mohammad Wasim Junior, Hasan Ali, Shahnawaz Dahani
West Indies: Nicholas Pooran (capt), Shai Hope, Shamarh Brooks, Akeal Hosein, Kyle Mayers, Rovman Powell, Keacy Carty, Jayden Seales, Keemo Paul, Romario Shepherd, Hayden Walsh Junior