Stoffel Vandoorne will stay on as a Mercedes Formula 1 reserve driver and will be joined in the role by Formula E team-mate Nyck de Vries.
Vandoorne raced for McLaren across 2017/18 before linking up with Mercedes in a support capacity, alongside his Formula E race duties.
Mercedes placed him on standby when Lewis Hamilton contracted Covid-19 last December but ultimately drafted George Russell into action to race at the Sakhir Grand Prix.
Vandoorne and de Vries subsequently both tested Mercedes’ W11 in Abu Dhabi last year.
De Vries, the 2019 Formula 2 champion, had a lengthy affiliation with McLaren prior to joining Mercedes’ Formula E squad.
Vandoorne delivered Mercedes’ maiden Formula E victory in Berlin last year while de Vries dominated the opening round of the 2020/21 season in Saudi Arabia at the weekend.