Nyck de Vries is in danger of losing his ninth place result at Monza after being summoned post-race to see the stewards.
De Vries is alleged to have driven “erratically” towards the end of the race, and will now face the stewards.
The Dutchman made a surprise debut on Sunday at Monza, after he was called up by Williams on Saturday morning to stand in for Alexander Albon.
Albon, who took part in Friday practice, was hospitalised with appendicitis.
De Vries endured a strong maiden race, running inside the points for much of the event before crossing the finish line in ninth, behind the Safety Car.
The 27-year-old has been linked with a full-time seat for the 2023 campaign at Williams, replacing Nicholas Latifi.
His performance on the track on Sunday makes for a strong case, however his hard work may well come undone if the stewards opt to hand him a time penalty.