The Australian made a bold move on Lando Norris on the opening lap, leaving his team-mate to trail behind for the rest of the race.
Piastri's aggressiveness seemed like a statement of intent, to show McLaren that he is still in this title fight and that he will not make it easy for Norris.
The 'papaya rules' were introduced over the radio for the first time at Monza, signalling that the drivers will be allowed to race but only if it is fair.
F1 legend believes McLaren must proceed with caution
With Norris closest to championship leader Max Verstappen, many would assume McLaren would help the British driver by ordering Piastri to make his life easier at times.
"You need to be very, very careful,” he said. “You need to be very careful because you can also destroy a young driver mentally if you suddenly don’t treat him fairly.
"And it can really break a trust. So it’s something very, very delicate, and then that’s why it’s so difficult to manage for them.”
The former Mercedes driver went onto explain how he felt Piastri deserves to fight for the title just as much as Norris does.
"“It is hard though on Oscar [Piastri] because Oscar in his contract, he’ll have a number one contract. It won’t say in his contract that you need to help Lando [Norris].
“And Oscar is driving brilliantly also, so he deserves actually every opportunity just from his point of view to get race wins.
“Plus, let’s also remember mathematically he can still be world champion, so there's also that.
“I mean he’s not that far behind Lando, it’s like, what is it 40 points or something that he’s behind Lando.
“So it’s hard to ask of Oscar to start forfeiting race wins potentially.”