Two OPEC+ sources said they did not expect the group to agree further output cuts on Sunday, when OPEC+ ministers gather at 2 p.m. in Vienna (1200 GMT).
Before then, OPEC ministers will meet at 11 a.m. on Saturday.
As the economic outlook worsened, several members of OPEC+ in April pledged voluntary cuts starting from May, adding to a 2 million barrels per day (bpd) reduction agreed last year.
A fourth source said the idea of formalising the voluntary cuts as an OPEC+ decision was being looked at.
Last week, Prince Abdulaziz told investors he said were shorting the oil price to "watch out", which many market watchers interpreted as a warning of additional supply cuts.
Prince Abdulaziz bin Salman, Prince Abdulaziz, Alexander Novak, Ahmad Ghaddar, Alex Lawler, Maha El, Kirsten Donovan
OPEC, Organization of, Petroleum, Saudi Energy, United, Thomson
VIENNA, OPEC, Russia, Vienna, Algeria, United Arab Emirates, Russian