Antonio Giovinazzi admits he has an eye on a Sauber seat for 2019.
Ferrari's other protege, Charles Leclerc, is linked with a move to the Maranello team for next year.
That would open up a place at Sauber for Italian Giovinazzi.
The 24-year-old tested both the Ferrari and Sauber cars in the post-Hungary test, declaring to Blick newspaper: "Both teams have improved since the tests in Barcelona."
He admitted he wants to race for Sauber in 2019.
"I'll run for Alfa Sauber four more times on Friday mornings in 2018. I then hope to get the seat that I want," he revealed.
Although slowest in 2017, Sauber is now on the rise, thanks in part to Ferrari's field-leading 2018 power unit.
Sauber is currently behind Toro Rosso in the constructors' championship, but Toro Rosso boss Franz Tost is worried.
"At Spa and Monza, we expect Sauber to be very strong with the new Ferrari engine," Tost said.
