Chinese driver Zhou Guanyu has joined the new Cadillac Formula 1 team as reserve driver.
Zhou will act as support for Valtteri Bottas and Sergio Pérez, who are both returning from a year out to race for the American team, and will be first in line should either be unable to race at an event.
Zhou had spent last year as reserve driver for Ferrari after three seasons as Bottas' teammate at the Alfa Romeo/Sauber team.
Team boss Graeme Lowdon, Zhou's long-time manager, said: "We wanted a candidate who had recent F1 driving experience, is prepared to work hard as part of a team and understands the challenges of developing a car throughout the season. Zhou fits the bill perfectly. He will be a great asset to us as we go racing in 2026."
Cadillac also have American driver Colton Herta on its books on a development deal. The former IndyCar race winner is taking the unorthodox step of racing in F1 feeder series Formula 2 this year as part of his push for a step up to the world championship in future.
Cadillac owners General Motors have already committed to racing with their own American-made engines by 2029.
In the mean time, Cadillac has a deal to race with Ferrari until their own engine project is ready.