Monisha Kaltenborn is once again missing in action this weekend in Russia.

Earlier in 2016, the Sauber boss and co-owner's paddock absence stirred speculation that the Swiss team's obvious financial problems may in fact be terminal.

However, Swiss newspaper Blick insists that Kaltenborn is only absent this weekend at Sochi in order to care for her unwell son.

More alarming, however, is that Tim Malyon, Sauber's head of track engineering, has suddenly left the struggling team.

Formerly at Red Bull, Malyon only joined Sauber a few months ago, to replace one of the team's longest-serving members, Giampaolo Dall'Ara.

"We have financial difficulties, it's not a secret, but I think the good thing is we are still around," said Sauber's long-time team manager Beat Zehnder in Russia.

"We're working hard to solve all the problems but it's not easy. An annual budget now [in Formula 1] is just massive and to cover it just by sponsors and the income from Bernie [Ecclestone] is just not sufficient."

As for whether Sauber will be able to make it through the rest of F1's longest-ever race calendar this year, Zehnder deferred to his absent boss.

"I think this is a question which Monisha should answer, because I haven't got the overall picture," he said.

Sauber remain pointless heading into the fourth racing weekend of the season.