Fred Vasseur believes it would have been impossible for Sauber to have continued in F1 as an independent team if Audi had not come on board.
Sauber, that currently oversees Alfa Romeo's entry in F1, will become the Audi works team from 2026 after the two parties recently entered into a strategic partnership.
Vasseur has confirmed Audi will provide the power unit - built under new regulations that come into force in just over three years' time - at its plant in Neuberg, whilst Sauber will oversee chassis development.
Looking ahead to Audi's arrival and what it means for Sauber, Vasseur said: "In the short-term, it won't have a big impact except that we know we can go to the next step.
"It will be a huge opportunity in terms of recruitment and to be more attractive for sponsors in the future.
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"Mid-term, for sure it's a game-changer that we have this kind of partnership because F1 is getting more and more difficult.
"F1 has made a huge step up over the last 10 years and to stay as an independent team today is quite impossible.
"It [the Audi deal] was probably the best option we could add so we are more than happy to have this kind of deal for the future."
The introduction of the budget cap was meant to level the playing field for the smaller teams in their attempt to compete with the likes of Mercedes, Red Bull and Ferrari.
Even with the budget set at $145million for last year and $140m for this season, Vasseur has confirmed Sauber is "still far away" from such a figure.
With Audi on board, Sauber now has the chance to push the cap to its limit and be more of a fighting force from 2026, in particular.
"We are fighting to be at the budget cap," said Vasseur. "We are absolutely dependent on the results.
"If you want to have a long-term view and you have only three or four independent teams it will become more and more difficult."