Former McLaren driver David Coulthard has hinted that the British team must contemplate dumping Honda.
There are claims that despite the millions in sponsorship brought by Honda, not to mention the free engine supply and manufacturer support, McLaren are nonetheless considering reverting to a customer engine deal with Mercedes.
Coulthard, who drove for McLaren for almost a decade, traced McLaren's current three-year predicament back to the philosophy adopted by the now-ousted team supremo Ron Dennis.
"This situation is a result of the mantra expressed by Ron Dennis that to win a championship, you have to be aligned with a manufacturer," Coulthard told The Telegraph.
"Well, Red Bull have shown most recently that this need not be the case. They won four world titles as a customer. What you do need is a manufacturer that gives you winning engine potential."
McLaren's current deliberations may also be related to their desire to hang on to Fernando Alonso.
The Spaniard's contract is up and former F1 driver Johnny Herbert told The Times that the current situation "might be the breaking point for Fernando".
Asked by Spain's El Confidencial newspaper if McLaren switching to Mercedes might influence his decision to stay in 2018, Alonso answered in Melbourne: "I don't know."
The 2017 world championship kicks off tomorrow with the Australian Grand Prix.