Sauber have subsequently done a deal to be powered by Honda power units for 2018, and Giovinazzi has gone on to ink a Friday practice deal with the Ferrari 'B team' Haas.
For 2018, it therefore appears possible that Sauber will take on a Honda-linked driver.
"At the end of the day it's the team's decision, and also the team's responsibility to have good drivers," said team boss Kaltenborn.
She also said that "in the past" Sauber has discussed the issue of driver choice with its engine supplier.
"And we have taken drivers from our engine supplier because it was the right thing to do," Kaltenborn explained.
"It's something we're open to and we'll see how it pans out."
As for a Honda-related sponsorship deal, Kaltenborn said it is "far too early" to speculate.