GP3 will only hold one race at the Monza circuit in 2017 after another had to be cancelled due to repercussions from a delayed Formula 1 qualifying session.
Its feature race will now take place on Sunday, while the sprint has been removed from the schedule altogether.
The event will get underway at 7.50am.
F1 qualifying was held back by over two-and-a-half hours due to continued rain showers making the track undriveable.
With F2 getting on track after this at 5.30pm, no other time can seemingly be found to accommodate the feeder series.
This is the second major interruption to its schedule after qualifying did not take place on Saturday morning, meaning that the grid has to be formed from practice times.
Honda junior Nirei Fukuzumi starts on pole, leading an ART 1-2-3-4 above Mercedes protege George Russell, Anthoine Hubert and Renault academy racer Jack Aitken.