As Red Bull ponders whether to stick with Renault or throw in its lot with Honda, the Japanese manufacturer admits to its own doubts.
Both Renault and Honda have made it clear that they need to know Red Bull's plans for 2019 as soon as possible, and while the official deadline by which time engine suppliers must notify the FIA of their plans for next season has passed, it would appear that the Austrian team is no closer to making its mind up.
Despite the various issues with Renault, not least the fact the French manufacturer has now returned to the sport as a constructor, Honda's partnership with Toro Rosso hasn't exactly set the world alight either… and as recently as China, a Renault-powered Red Bull was winning.
As eager as anyone to hear Red Bull's decision, Honda motorsport boss Masashi Yamamoto admits he too has reservations.
"We regard it as a positive thing, giving us time means we have time to consult more," he said, according to Motorsport.com. "We are very positive. To deal with Red Bull is a really big thing for Honda, because they are a top team.
"This gives us a sort of pressure as an engine manufacturer," he adds. "We have to consider many aspects very well, can we really deal with Red Bull's size? We have to feel the responsibility to supply the engine."
It's understood that Honda, which held further talks with Helmut Marko in Spain, is looking to promote one of its two proteges, Tadasuke Makino and Nirei Fukuzumi, who are currently in F2, to F1 providing they accrue the necessary superlicence points.
With Red Bull clearly unwilling to accept such a move, it is likely that Toro Rosso would be required to provide a berth for one of the youngsters, a prospect that makes sense should Daniel Ricciardo opt not to remain at the Milton Keynes squad and Pierre Gasly replaces him.
Technical boss, Toyoharu Tanabe, who would likely be head of the entire Honda F1 operation, admits partnering with a proven winner again would be relief after the break-up of the partnership with McLaren.
"It was difficult with McLaren," he admits, "but it was also a very good experience. They gave us very precious experience as a partner.
"We are now having another experience with Toro Rosso, which is very good. If we are going to be with Red Bull, we don't think we'll be together like McLaren. I don't think we'll have the same situation as we had like McLaren."