Having already secured the signature of German driver Nico Hulkenberg for 2025, Sauber are on the hunt for the perfect pairing, which neither Bottas or Zhou are expected to play a part in.
Which team could Bottas move to?
With the Finnish driver anticipating a necessary team switch, his name has been mentioned among the lower teams on the grid.
Ever since Lewis Hamilton's pre-season Ferrari announcement, Carlos Sainz has been at the centre of the hectic driver market with a move to Williams almost everything but confirmed.
Reports now suggest however that it could be Bottas who partners Alex Albon at James Vowles' team, given Sainz appears to have gone cold on the deal.
Having made his F1 debut with the Grove-based outfit in 2013, Bottas could make a return by replacing Logan Sargeant, given the American's consistently poor performance in the sport.
Formu1a.uno report: "While teams want the best talent available, signing someone with enthusiasm and confidence in a team’s trajectory is essential.
"Partly because of this, Valtteri Bottas is a candidate who ticks all the boxes for the Grove-based operation. He is an experienced and capable driver who will undoubtedly push Alex Albon to raise his level. In such a hotly competitive midfield, having two drivers competing at a high level is essential."
The move is yet to be confirmed by either Bottas or Williams.