They are three time Olympian and four time Pacific Games 400m hurdles Champion Mowen Boino, double Pacific Games 400m champion and London 2012 representative Nelson Stone and rising star in the 200m and 400m Theo Piniau.
Athletics PNG last year named the three contenders for this place and set out how the selection process will work.
The athlete selected will be the one who, by the PNG Olympic Committee deadline of June 19, has the best performance by reference to the IAAF scoring tables in Athletics.
The tables are a recognised method of comparing performances in different events, with each performance being worth a certain number of points.
The better the time the more points it is worth. Whoever has the best performance this year up to June 19 will be selected.
Athletics PNG President Tony Green said it will be very competitive.
He said both Nelson and Mowen are determined to make it to Rio and with Theo improving it could be an one of these three.