Mercedes completed a two-day Pirelli tyre test this week as Lewis Hamilton and George Russell returned to action for the first time in 2023.
Pirelli arranged the extra tests for late 2022 and early 2023, with Mercedes in action across Wednesday and Thursday at former French Grand Prix venue Paul Ricard.
Russell drove the 2022-spec W13 on Wednesday before handing over to seven-times champion Hamilton on Thursday.
AlphaTauri is due to participate in wet-weather running at the venue across Friday and Saturday.
Mercedes is set to run the W13 again during another tyre test at Jerez next week, where it will be joined by Aston Martin.
McLaren has also been on track this week in its 2021-spec MCL35M.
Lando Norris drove the car at the Circuit de Barcelona-Catalunya on Wednesday before handing over to new team-mate Oscar Piastri.