The Mercedes driver would normally have been among the favourites at his home race, but the Formula 1 championship leader will instead start from the back of the grid after exceeding his allocation of several engine components.
Mercedes team principal Toto Wolff admitted the decision was difficult, given Antonelli will miss the opportunity to fight for victory in front of his home supporters.
However, Mercedes believes Monza is the best circuit at which to accept the penalties as it looks to maximise Antonelli’s chances over the remainder of the championship.
“Our theory, our calculations say that it’s the best track to take it,” Wolff said.
“Obviously, algorithms don’t consider the nationality when we have to fight for a championship and want to get the most PR, so that’s what we’re going to do.”
Mercedes will replace all the major power unit components available to it, including the internal combustion engine, turbocharger, MGU-K, energy store and control electronics.
Not every component change will result in an additional penalty for Antonelli, but taking a fifth internal combustion engine, fourth energy store and fourth control electronics unit leaves him with a combined 30-place grid penalty.
That will effectively send the 20-year-old to the back of the field at Monza.
George Russell faces a similar situation, although Mercedes has yet to decide where the British driver will take his own penalty. Russell has also used an additional turbocharger this season.
“With George, the discussions are ongoing on where to take it,” Wolff said.
The Italian Grand Prix takes place at Monza from 4 to 6 September, with the race on Sunday, 6 September.
