Christian Horner fears that Red Bull's failure to promote Japanese star to the 'big team' will cause him to look elsewhere.

Tsunoda's post-season outing in the RB20 in Abu Dhabi had many hoping that the youngster might replace Sergio Perez when the inevitable happened, however, other than the fact that the test had been planned some time before, when the Mexican's fate wasn't quite as precarious, the fact is that whereas Liam Lawson is a protege of the Red Bull young driver programme, Tsunoda has always been backed by Honda.

While the Austrian team appreciates his speed and determination, fans have come to love the Japanese driver's attitude, especially his radio outbursts, however with Lawson given the nod over the seat alongside Max Verstappen Horner believes that 2025 will be Tsunoda's final season at RB.

"We're acutely aware that if we're not able to provide an opportunity for Yuki in all honesty this year, does it make sense?" said the Red Bull boss when asked if the Japanese might follow Honda to Aston Martin in 2026.

"You can't have a driver in the support team for five years," added the Briton. "You can't always be the bridesmaid. You've either got to let them go at that point or look at something different.

"I think he's very determined," he continued. "He knows that things change very quickly. Who would have thought nine months ago that we'd be sitting here talking about Liam Lawson being our driver for 2025?

"Things change quickly in this industry and he's aware of that and he knows that he needs to be the one demonstrating that he's the one knocking on the door.

"Is great to have Yuki still involved with the Racing Bull scene next year," he added. "And of course he's on standby should he ever be required."

Tsunoda's teammate for 2025 will be Isack Hadjar, while waiting in the wings is another Red Bull protege, Arvid Lindblad.

Asked about the decision to promote Lawson over Tsunoda, Horner said: It was very, very tight between the two of them.

"I mean, Yuki is a very fast driver," he continued. "He's got three or four seasons of experience now. He did a very good job in the tyre test for us in Abu Dhabi where the engineers were impressed with how he performed.

"With Liam, when you look and go into the analytics of his race, pace was slightly better in the races that he did. His qualifying pace was very tight with Yuki, and you've got to assume that the potential with Liam having only done 11 grand prix, is he's only going to get better and stronger. He's shown real mental resilience and toughness.

"A couple of things have stood out with me with Liam," he added, "how versatile he is. You put him into a situation, he gets on with it. If you remember his debut in Zandvoort after Daniel broke his fingers, he was racing against Max on his out lap.

"He's got that kind of gritty racer mentality. He did a year in the DTM where he adjusted to driving a Ferrari GT car incredibly quickly alongside Alex Albon and generally had the upper hand. And again, his race-craft has been really one of his key strengths. So he's not afraid to go wheel-to-wheel and even rub wheels where necessary. So I think he's going to do a great job for us. The engineers have enjoyed working with him through the running that he's done this year. He's got a good work ethic as well."

However, in terms of pushing the New Zealander, Horner admits that lessons have been learned in terms of his predecessor.

"I think the key thing is not to put too much pressure on him and not to put too much pressure on himself that he's going out against the best driver of his generation.

"I think that he just needs to almost ignore the data of what's going on on Car 1 and just focus with his own engineering team, what he's doing, and just do the best job that he can and he'll be fine. And hopefully we can support him in that.

"Hopefully we'll be able to provide a car that suits him as well as Max next year, and we'll see how he goes."