Two other Formula 1 teams will be able to call upon the services of Mercedes’ reserve drivers in the event that they require a substitute in 2020.
Reigning World Champions Mercedes has ex-McLaren driver and Formula E racer Stoffel Vandoorne and former Sauber and Haas pilot Esteban Gutierrez as back-up to Lewis Hamilton and Valtteri Bottas.
It has now been confirmed that the pair will also act as reserve drivers for McLaren and Racing Point, in the event that the respective teams need a stand-in.
McLaren had a similar arrangement with power unit supplier Renault last year when it had Sergey Sirotkin on standby.
A reserve driver has not been drafted in to race since 2017, when Paul di Resta filled in for an unwell Felipe Massa for Williams in Hungary.
Formula 1 CEO Chase Carey indicated earlier this week that a grand prix would not be abandoned in the event of a race driver testing positive for coronavirus, pointing to the presence of reserve drivers.
Ferrari officially has Alfa Romeo racer Antonio Giovinazzi as its reserve driver while ex-Williams racer Robert Kubica is the nominated back-up at the Switzerland-based team.
Red Bull Racing and AlphaTauri has long-standing test driver and ex-Toro Rosso racer Sebastien Buemi, along with Brazilian youngster Sergio Sette Camara, as its reserve drivers.
Guan Yu Zhou (Renault), Pietro Fittipaldi and Louis Deletraz (Haas) and Jack Aitken (Williams) fulfil the role elsewhere.