Sauber have been biding their time when it comes to deciding their driver line-up for next season. Valtteri Bottas and Zhou Guanyu have had to endure one of the most difficult seasons in recent Formula 1. Sauber – in their various guises – have slowly been slipping down the Formula 1 pecking order. READ MORE: Everything you need to know about Stake F1 Team Kick Sauber from team principal to Audi future In the previous five seasons as Alfa Romeo, the Swiss outfit only finished above eighth in the Constructors’ Championship once. Bottas and Zhou have yet to score a point this year after 18 race …