Valtteri Bottas has raised the possibility of returning to the Mercedes Formula 1 team in a reserve role if Sauber, the future Audi team, drop him at the end of the season.

The 35-year-old won 10 grands prix driving for Mercedes alongside Lewis Hamilton between 2017-2021 before joining Ferrari-powered Sauber in 2022.

"Firstly, the priority is to stay as a race driver -- that is what I want, and that is what we are pushing for," Bottas told reporters at the Mexican Grand Prix.

"But of course, as I don't have anything signed, we are in October and I've got to look at all the alternatives. That includes going back to the Mercedes family.

"That's for sure one option and I would consider it, but there are other options as well."

Sauber boss Mattia Binotto told Reuters he expected a decision by mid-November on the last vacancy on the 2025 starting grid.

Mercedes also supply engines to Williams, Bottas's first team, and McLaren and are expected to add Renault-owned Alpine to the list from 2026 when the French manufacturer stops making its own power unit.

Aston Martin will also use Mercedes engines next year before switching to Honda power.