Valtteri Bottas will leave Sauber after the 2024 Formula 1 season but is understood to already be close to signing back with Mercedes as its reserve driver from next year.
In what has been an awful year for Sauber – still 2024's only point-less team – Bottas's place beyond the deal he struck when leaving Mercedes at the end of the 2021 season, when Sauber was branded as Alfa Romeo, was threatened as plans for Audi's 2026 arrival accelerated.
First, Sauber hired Haas driver Nico Hulkenberg in a deal covering the 2025 season ahead of the Audi rebrand for the following year, with Bottas's team-mate Zhou Guanyu departing the outfit.
Sauber then entered a turbulent period of management change, with previous bosses - former CEO Andrea Seidl and chairman Oliver Hoffmann - axed and ex-Ferrari team boss Mattia Binotto hired as chief operating and chief technical officer. Red Bull sporting director Johnathan Wheatley also joined to be Sauber team principal from 2025.
In Brazil last weekend Bottas said doing a new deal with Sauber was still "what I'm pushing for with Mattia".
But over the Sao Paulo Grand Prix weekend Autosport reported that Formula 2 championship leader Gabriel Bortoleto has agreed a deal to race for the Swiss team for next year after it missed out on signing Williams-bound Carlos Sainz, its long-held target.
"A situation like this is never easy for anyone," Bottas said. "But after all the good and in-depth discussions we had in the past weeks, we realised that the conditions to grow this project together were not met.
"These past years with the team have been an incredible journey, full of growth, challenges, and unforgettable moments. I’m grateful for the joint experiences as well as the trust and support I’ve felt every step of the way.
"Though it’s time to move on, I’ll always carry a piece of this team with me, and I look forward to seeing what the future holds for us both."
Mattia Binotto, COO & CTO, Sauber Motorsport AG added: “We extend our deepest gratitude to Valtteri for the past three years together. He has been the embodiment of professionalism, using his vast experience to support the team’s growth.
"Valtteri’s dedication and approach have been invaluable during a pivotal time in our history, and the memories of these years will stay with us for a long time. In considering our driver line-up for the coming seasons, Valtteri was unquestionably a key candidate.
"With his fighting spirit, he frequently pushed the car beyond its performance limits. However, a decision had to be made. After open and constructive discussions, we mutually concluded that final conditions could not be met so we agreed that it is time to part ways. Valtteri will always have an open door here in Hinwil.”
Sauber's decision means Bottas's current F1 racing career will likely be capped at 10 wins from 246 races, come the end of the current campaign in Abu Dhabi next month.
But he could yet see more action with his former team, after saying returning to what he called the "Mercedes family" at Interlagos was "for sure one option and I would consider it".
Autosport understands that discussions between Mercedes and Bottas have been going on for several weeks, with the squad set to field a team made up of drivers it has supported all the way to F1 – George Russell and Andrea Kimi Antonelli – in 2025.
Although the path back to the full-time racing driver from a reserve role is difficult, F1 has had a surge in super-sub appearances in recent years.
This was turbocharged by the COVID-19 pandemic, with Hulkenberg, in particular, gaining a series of unexpected appearances for what is now Aston Martin after leaving Renault at 2019's end.
Injury replacements have been required elsewhere and this year Williams axed Logan Sargeant well before the end of the current campaign, although opted to replace him with its junior driver, Franco Colapinto.
But Hulkenberg's story is one particularly relevant to Bottas, as it was his regular place in the F1 paddock as Aston's reserve that helped him stay in regular contact with then Haas team principal Guenther Steiner and eventually to a deal to rejoin the grid as a full-time racer with the American squad in 2023.
It is not currently known when any deal for Bottas to return to Mercedes might be announced, but Sauber is predicted to be confirming the deal for Bortoleto – currently a McLaren junior – this week.
