The Spanish driver rested at the team hotel, with hopes he will be fit to race this weekend at Interlagos.
“Unfortunately, Carlos is unwell and will not be coming to the track today, so all mandatory media slots will be cancelled. Apologies for any inconvenience,” a Williams spokesperson said.
Sainz’s absence comes at a critical stage for Williams, which is targeting its highest constructors’ championship finish since 2017. The Grove-based team currently sits fifth, 39 points clear of sixth-placed Racing Bulls.
The 2025 season has been a strong one for Sainz, who took Williams’ first podium since 2021 at the Azerbaijan Grand Prix and repeated the result in the Sprint race at the United States Grand Prix.
He enters the weekend 11th in the drivers’ standings, trailing teammate Alex Albon by 35 points.
Sainz’s illness echoes a scare last year at the Saudi Arabian GP, when appendicitis forced the then-Ferrari driver out of the race, and Haas driver Oliver Bearman stepped in to score a seventh-place finish on his debut.
The news comes off the back of a big week for Williams, with the team announcing a rebrand ahead of next season and running a special Gulf Oil-themed livery this weekend in Brazil.
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