Guanyu Zhou admits he needs to be "careful" not to be pushed off the Formula 1 grid.
It is the 24-year-old Chinese driver's second season on the grid this year with Alfa Romeo, who are now beginning the transition to full works status and Audi ownership and control by 2026.
Valtteri Bottas, already under contract to Alfa Romeo-Sauber for 2024, said he thinks Guanyu deserves a new deal.
"He's made a big step in performance but also confidence and technical knowledge," said the Finn. "I think he really deserves a place in Formula 1."
However, there are rumours of problems with negotiations between Zhou's Chinese backers and the complex new management at Sauber - with Andreas Seidl mainly factory-based and handling the preparations for the Audi future.
Guanyu admits his place for 2024 isn't secure.
"That's of course the goal," he is quoted by Sky Deutschland. "But it's not easy because of Audi coming and all of these things, and they need a little more time.
"For me of course it's better to have a longer contract to be a little more relaxed than just getting a one-year contract again," Zhou added.
It is believed the driver most likely to potentially replace Guanyu is Sauber junior Theo Pourchaire - who is poised to win the Formula 2 title this year.
"There aren't many vacancies left," Zhou admitted, "so I'm very careful to stay where I am."
