The Italian's qualifying session was cut short on Saturday as he suffered an engine failure towards the end of Q1, with subsequent red flags seeing him finish in 15th.
Giovinazzi was set to start the race at the Circuit Spa-Francorchamps from 13th on the grid however Alfa Romeo elected to fit a new engine rather than return to an old specification.
Giovinazzi had Ferrari's updated engine powering his car throughout the weekend, as the Italian manufacturer is likely to use it at its home race in Monza next weekend.
The Pole has been fitted with a different spec engine, turbocharger and MGU-H, as well as a different spec rear wing assembly.
Kubica failed to set a lap time on Saturday as he had an engine failure during Q1. However, he was permitted to race by the stewards after a request from the Williams team.
Bahrain International Circuit - Winter testing