Ricciardo is back at Red Bull this year as their reserve driver. But he has made it clear he wants that to be a temporary arrangement.
It remains to be seen what opportunities for a race seat will arise for next season. It may be that Red Bull has an in-house vacancy open, given the situation at sister team AlphaTauri.
Nyck de Vries was signed to replace Pierre Gasly but has struggled so far this year. He has yet to score a single point for the team and is in danger of losing his seat, perhaps even before the end of this season.
If that happens, it is understood Red Bull will look to their driver academy as their first port of call in the search for a replacement. Liam Lawson is likely to be the driver deemed most prepared for an F1 debut, given his impressive performances in Super Formula so far this year.
And they will not be short of other options with the likes of Ayumu Iwasa and Isack Hadjar among the six juniors they have racing in Formula 2 this year. If none of them are deemed to be ready, though, then AlphaTauri could turn to Ricciardo.
Team principal Franz Tost admitted as much as he spoke to reporters at the Austrian Grand Prix. He said: "The philosophy is quite clear – performance decides. Of course, the team philosophy is to educate young drivers but if young drivers are not currently there...
"Some good young drivers are coming – Iwasa is doing a good job, Hadjar is doing a good job – but it's simply a little bit too early for them. I see them later in our team. If the time is too early then maybe we have to find another solution, but this has not been discussed so far."
Despite some questions over Ricciardo after his struggles at McLaren, Red Bull chief Horner insists the Aussie would be raring to go if the chance came. He said: "He's going to be driving our car for the first time after the British Grand Prix and he's obviously a world-class driver.
"So I think the first thing will be to see how he performs and where his motivation is, and then from there, it's a question for AlphaTauri as to their choices for the following season.
"When he when he first arrived after Abu Dhabi last year, it was a little bit of a shock because we didn't really recognise him from the driver that had left us a few years earlier. But he seems to have rediscovered his mojo, he's been working hard on the simulator, he's now extremely competitive in what he's doing in the virtual world.
"So, whether that crosses over into the real world, you know, we'll see, albeit at a tyre test. We'll get an impression as to the level that he's performing at. But, certainly, you can see that there's a spring coming back in his step."