Jehan Daruvala tested for McLaren last month at Silverstone and will undertake another two days of testing with the papaya squad on Monday and Tuesday at Portimao.
It's unclear why McLaren has granted the Indian racer several outings onboard its 2021 MCL35M as the 23-year-old is supported by Red Bull.
But the tests are perhaps part of a personal programme set up by Daruvala.
McLaren's test team has been on site at Portimao since last week where it ran IndyCar star Colton Herta and sim driver Will Stevens.
"My first taste of Formula 1 machinery was surreal and I can’t wait to get back in the car again in Portimao," commented Daruvala.
"I came away from the Silverstone test with a lot of confidence as both from a driving and physical perspective I did well and covered more than two race distances absolutely trouble-free.
"My dream has always been to race in Formula 1 and this test will build on what we achieved at Silverstone."
A three-time winner in the FIA Formula 2 Championship in which he has raced since 2020, Daruvala currently sits fourth in the series standings with Prema Racing.
Keep up to date with all the F1 news via Facebook and Twitter
Max Verstappen will launch his long-awaited Nürburgring 24 Hours debut from the second row of…
Cadillac F1’s arrival on the grid in 2026 has been anything but quiet, and according…
Alpine has strengthened its growing 2026 Formula 1 project by officially welcoming former FIA head…
The 65th running of the Indy 500 held back in 1981 saw an interesting and…
Ralf Schumacher has opened up about the emotional strain he experienced during his F1 career,…
For most Formula 1 drivers, the biggest threat during a Grand Prix weekend comes on…