As a 10-time race winner and previous runner of Mercedes-powered engines, Bottas will offer the team a safe pair of hands behind the wheel if required, as well as providing feedback from the garage.

Bottas can step in to replace George Russell and Kimi Antonelli - the 18-year-old rookie who has been dubbed the sport's next Max Verstappen - at short notice.

However, Bottas' services will also be available to two other teams, McLaren and Williams, providing their needs do not clash with the German manufacturer.

According to RacingNews365, there is no formal agreement in place to ratify their arrangement, but the three teams will be able to share Bottas between them this year.

That means if Norris, Sainz, Oscar Piastri or Alex Albon are incapacitated, he can step into their respective cars.

In the past, McLaren and Williams both had the option to rely upon the Mercedes reserve driver pool as part of their collaboration and power unit partnership.

Mick Schumacher was the reserve driver for the Brackley-based squad in 2024 and, while the German was not asked to step in, the son of F1 legend Michael Schumacher would have been eligible to drive for Williams if they needed him.

Despite Bottas' past experience at Mercedes, it is not expected that he would be drafted in to replace Antonelli if he struggles. The youngster crashed in brief drive during FP1 at Monza last season and has only raced at Formula Two level.

But when announcing the deal, Wolff said that Bottas he would be there to "support" Russell and Antonelli.

"His impact and contribution in the five years he was with us previously as our race driver was immense," the Austrian said.

"Along with scoring multiple Grands Prix wins, he played a vital role in five of our championship victories., His technical feedback and input were important in helping us to those successes and pushing the team forward.

"In his role as Reserve Driver, all those qualities will be incredibly important in helping us compete for world championships and supporting both George and Kimi on track."