Pakistan captain Azhar Ali won the toss and chose to bat in the third one-day international against Sri Lanka in Colombo on Sunday.
Sri Lanka drew level in the five-match series in Pallekele on Wednesday after Pakistan won the opening match at Dambulla last Saturday.
Pakistan retained all-rounder Mohammad Hafeez even though he is banned from bowling for a year due to an illegal bowling action. Hafeez scored a century in the first game.
The tourists replaced batsman Babar Azam with debutant left-arm spinner Imad Wasim to bolster the bowling.
Sri Lanka picked an unchanged side.
Ninth-ranked Pakistan need a series win to remain in contention for a place in the eight-nation Champions Trophy in England in 2017.
Sri Lanka, currently ranked fifth, are assured of taking part in the tournament.
