Frederic Vasseur has admitted Sauber is aiming to replace ousted technical boss Jorg Zander as soon as possible.
It is believed Zander was let go over a spate of alcohol-related incidents.
"I’m the boss and I decided that this decision was right for our future," team boss Vasseur said.
Asked if it was a personal issue, he answered: "If everyone was happy, he would still be here.
"The goal is ideally to replace Jorg Zander as soon as possible. But we have to consider that potential candidates are currently under contract elsewhere.
"I want to find a solution for Sauber but it has to be the best one. We can fill the post or we can work collectively," Vasseur explained.