Alfa Romeo is yet to decide if Chinese rookie Guanyu Zhou will remain Valtteri Bottas' teammate in 2023.
Recently, the Swiss-based team's technical boss Jan Monchaux said 23-year-old Guanyu had been "a surprise of the season".
"If you read back some of the comments of journalists last winter, they were quite sceptical - to remain diplomatic," he said.
"And he's a great driver."
However, with Alpine refugee Oscar Piastri now regarded as a key to the 2023 driver 'silly season', it appears Sauber is leaving that seat open for now.
Team boss Frederic Vasseur, for instance, has pointed out that Guanyu's presence in Formula 1 has not really worked out from a commercial point of view.
Auto Motor und Sport said only two Chinese companies are currently on the Alfa Romeo livery.
"It's not enough for Chinese companies that a compatriot is in Formula 1," Frenchman Vasseur said.
"They only work with you if the performance is right."
Meanwhile, Vasseur made clear that he is opposed to Mercedes' and the FIA's push to make significant anti-'porpoising' rule changes for 2023.
"One change often involves many others, and what we really need is the opposite - stability in the rules to keep costs down," he said.
"Formula 1 teams are famous for creating problems but also solving them."
