The Russian deal was hailed as Sauber’s saviour, but rumours persist that the Swiss team is not yet out of the woods.
Reports spoke of an enormous investment by the government-linked Russian entities, but then it was suggested that only Sauber’s most pressing debts would initially be paid.
And Welt newspaper said the deal could collapse altogether if 17-year-old Sergey Sirotkin’s preparation for a race seat next year fails.
The German report said Sauber’s Russian deal will only actually be realised when Sirotkin gets his FIA super license.
"Until then," said Welt, "only ten million euros will flow, paying off the most pressing debts".
Ferrari is also playing a key role in Sauber’s situation, with the Italian team reportedly still waiting for a EUR 19 million engine bill to be paid.
An ultimatum may even have been issued: at least 9 million in the next week, or no customer V8 power will be turned on at Spa after the summer break.
The newspaper also said Ferrari engineers are wary of the Russians, whose government-linked technology companies could scoop top-secret technical information.
Sauber team boss Monisha Kaltenborn’s 19-minute press round with reporters in Hungary on Saturday also heightened suspicions that the Russians have not yet arrived to the Hinwil based team’s final rescue.
"It sounded like a politician," one voice said after leaving the Sauber hospitality, according to Speed Week. "A lot of talk, but what was said?"
She did, however, play down rumours the deal could see her leave Sauber.
"As you can see, I’m here," said Kaltenborn.
She also had a message for the doubters.
"We are only at the beginning," said Kaltenborn, "so we’re not thinking about what we will do if something goes wrong. That would be pure speculation.
"And no one ever said that everything depends on one driver.
"It is true that we have not communicated everything we really want to say, but that doesn’t mean you should jump to conclusions.
"We know from our previous partnerships, for example with Petronas, how many details need to be clarified."
Sauber is obviously juggling several balls at present. One the one hand is a suspicious and disgruntled Ferrari, who nonetheless want to ink a new deal with the Swiss team for a customer supply of V6 power next year.
And according to another rumour in Hungary, Sauber may be hoping that Sirotkin can earn his mandatory FIA credential at the wheel of an old Ferrari car.
Kaltenborn said a lot of unanswered questions will be answered in a forthcoming press release.
But she did deny that the Russian deal could see Sauber’s partnerships with Mexican sponsors, and therefore Esteban Gutierrez’s career, end.
"One thing has nothing to do with the other," insisted Kaltenborn.