Marcus Ericsson has admitted that the identity of Sauber's engine supplier for 2018 is in doubt.
Earlier, the Swiss team inked a contract to become Honda's first F1 customer, but rumours suggest the deal could now be scrapped.
"To be honest, a lot has happened over the past few days," Swedish driver Ericsson said.
"Frederic [Vasseur]'s first priority is to look into the matter."
Asked if he would be happy with a Honda engine next year, Ericsson answered: "If Honda is 100% focused on success, then it's good for Sauber. Otherwise not.
"I understand the question, but I don't really know what to think of it."
Meanwhile, amid speculation that Ericsson is too closely linked to Sauber's new owners, incoming boss Vasseur told L'Equipe: "The future of a team should not depend on a single driver.
"I will have the last word on the driver question in the future."
The 2017 championship continues on Sunday with the British Grand Prix.
