Mick Schumacher has completed a private test for McLaren at Portuguese circuit Portimao as part of his role as Mercedes' reserve driver.
Schumacher, son of seven-time world champion Michael, joined Mercedes this year after being released by Haas at the end of 2022.
Mercedes shares its test and reserve drivers with McLaren, which races with the company's engines.
Schumacher would be the stand-in if either Lando Norris or Oscar Piastri are unable to race for McLaren, or if Lewis Hamilton and George Russell cannot do so for Mercedes.
The 24-year-old tested for Mercedes in Barcelona earlier this year.
Schumacher completed the Portimao test in the team's 2021 F1 car with a separate McLaren crew to the one which will travel to Silverstone for the British Grand Prix this weekend.
The test was to familiarise Schumacher with McLaren.
"Joining Mick are some of our mechanic and engineering apprentices and interns, gaining valuable experience working in a trackside environment," McLaren said on Twitter.
Mercedes boss Toto Wolff is known to be keen to find Schumacher a race seat for 2024, but it remains to be seen if the German driver will race in F1 again.