Niki Lauda has dodged speculation that Mercedes could step in to help McLaren solve their performance crisis.
Rumours swept the Melbourne paddock last weekend that, now into their third disappointing season with works engine partner and sponsor Honda, McLaren are finally looking for the exit.
It is speculated that Eric Boullier is behind a plan to offload the Honda deal to Sauber, and tie up a return to customer Mercedes power for McLaren - perhaps even within this season.
"I cannot comment on this because I do not know about it," Mercedes team chairman Lauda is quoted as saying by Germany's Sport1.
In Melbourne, Mercedes chief Toto Wolff was also asked about the McLaren rumours but would not comment except to say he wants a "level playing field" in F1 as well as multiple manufacturers on the grid.
Yet one theory is that Honda have now acknowledged their major design error with the 2017 power unit, and are rushing to introduce a new concept in the next two months.
"In two months, around the Monaco Grand Prix, Honda hopes to have a new engine," former F1 test driver Bas Leinders told Belgian news agency Sporza.
However, amid signs that the Spaniard's long patience is also now up, Fernando Alonso does not sound optimistic.
"There has to be a miracle from god to help us - something more than we are doing at the moment," he is quoted as saying by Spanish sports daily AS.
McLaren's Stoffel Vandoorne and Alonso finished 13th and 14th respectively in Melbourne.
