The right-wing conservative grouping's leader, Jarosław Kaczyński, said a decision will be "completely clear" by March.
Sources close to the party told the Polish Press Agency (PAP) that four names are under consideration, all under 50 – an age threshold Kaczyński himself has reportedly emphasised.
They are: Zbigniew Bogucki, head of the Presidential Chancellery; former education minister and party deputy leader Przemysław Czarnek; former deputy sports minister and deputy leader Anna Krupka; and MEP and deputy leader Tobiasz Bocheński.
Former prime minister Mateusz Morawiecki, who leads one of several warring factions within the party, is not on the list.
Kaczyński is said to want a candidate free of political baggage who can appeal to right-wing and patriotic voters, according to PAP.
The announcement is expected to take place at a large party convention, with one PiS parliamentarian saying the new face would "inject fresh energy" and effectively launch the campaign early.
The party has been dogged by internal tensions since November last year, when a rift emerged between Morawiecki's supporters and a rival grouping.
Kaczyński recently warned that anyone stoking further public infighting would be suspended from the party.
Under the constitution, Poland's next parliamentary elections must be held by early November 2027.
(ał)
Source: PAP