As reported by Motorsport.com in June, Valtteri Bottas is primed to agree terms with Cadillac to complete his return to a Formula 1 race seat. This leaves just one much-coveted seat as the grid expands to 22 cars, and everyone without a contract next year has been linked to it.
Of them, Sergio Perez is considered the most likely and most attractive candidate to the team, given his experience and support from Mexico. From a geopolitical standpoint, an American team linking up with a Mexican driver feels somewhat incongruous, and F1's bubble is not entirely impervious to global affairs, but you'd expect it not to be a factor here.
