But as paddock whispers emerged in Monaco that the Spaniard is in talks with the Grove-based squad, a deeper analysis of what the team can offer shows it might not be such a crazy option for him.
Of course, as a driver at the top of his game who has shown he can fight on equal terms with the very best, Sainz’s preference is obviously be to keep himself in a race-winning seat for 2025.
But with Red Bull and Mercedes clearly not falling over themselves to snap up the Spaniard, as they edge towards committing to other options, Sainz has been left with a rapidly dwindling set of options.
The easiest choice for him would be to take the money and security of a long-term works deal with Audi.
It would guarantee him several years in F1, the full support of a manufacturer team and the possibility to be part of an exciting new project.
But equally it is not without its risk and downsides – and the biggest is that it could be a step backwards in competitive terms for quite some time.
While Audi is throwing a tremendous amount of money at its F1 entry and the creation of its new 2026 power unit, the Sauber team it bought is coming from quite a long way back.
Off the back of some under investment in recent years, Sauber is needing to get on with a recruitment drive to lift it up to the level of other teams; while the infrastructure at its Hinwil factory needs ramping up too.
Those are things that take time to have an impact and, with its current car struggling to deliver the consistency needed to fight for points right now, the reality is that there is unlikely to be a major change in fortunes next year.
That could mean Sainz, if he takes up the Audi offer, of moving from a Ferrari team that is fighting for wins each weekend, to a Sauber squad that may well be fighting to get out of Q1. That's not a very exciting prospect.
Williams right now looks to be not much better than Sauber in outright pace terms, but the team has been clear about the potential it sees for rapid improvement.
That could well be the reason why team boss James Vowles went so public last weekend in Imola in revealing that the squad’s FW46 is well overweight – and giving away a bunch of lap time that is easily recoverable.
“The car this year that we've been running is about four and a half tenths a lap slower, every lap, by the fact it is still overweight,” said Vowles, who thinks it can shed the majority of that excess over the next few races.
If you take off the 0.45 seconds that Vowles says is being left on the table just through weight, then that transforms Williams’ competitive situation.
Beyond the weight factor, Vowles is also making use of investment from team owner Dorilton Capital to ramp up Grove’s infrastructure and get it on an even terms with the squads it needs to be fighting against.
And there was perhaps no better proof of conviction about the team’s future than the fact that Alex Albon, who was understood to have had a first option of refusal from Red Bull for 2026 if it had a free seat then, electing to turn that chance down in favour of committing to his current team.
Perhaps Williams' early move to get Albon locked down was equally about showing other drivers about the promise for the future.
Longer term too, especially as F1 heads to the all-new rules era for 2026, that Williams has a Mercedes customer engine deal already in place is a bonus – as there remain repeated whispers that the German manufacturer’s dyno testing is showing some impressive results.
But perhaps the biggest attraction that Williams could offer Sainz over Audi is flexibility.
The Audi offer would tie him down for the long term, meaning he would be locked into whatever the German manufacturer produces right now – which could be quite a gamble.
That could be great news if Audi hits the ground running, but if things take a while to get up to speed – and let’s not forget how Honda struggled with its early turbo hybrid engines – then Sainz could lose the best years of his career.
As he said in Monaco on Thursday: “I can just tell you that with such an important decision at this stage of my career, that I want to have all the cards on the table to take the right one – and think about it carefully.
“I’m about to be 30 this year and the next project is a project that I really want to make it work and see how it goes.”
Williams would take Sainz with open arms and that would likely mean being happy to even offer him a deal that could allow him to become a free agent for 2026.
It would mean if it can prove next year it is heading in the right direction, and the reality of the Mercedes project for the new rules becomes clearer, then it would have the chance to convince him to stay.
But equally that flexibility would allow Sainz to have the possibility to become a player for the 2026 market – and potentially one of the biggest names who is free if top seats open up.
For 2026, Max Verstappen could be on the move if Red Bull’s engine project does not look like it going to deliver all that is hoped, while Sergio Perez would not be guaranteed.
George Russell will also be out of contract at Mercedes, while the fate of its second seat at the Brackley-based squad is unclear.
There are some tempting options that could open up that have not happened this time around.
For now, nothing is decided, with Williams also in talks with Valtteri Bottas as it weighs up who best to slot in alongside Albon.
But once this Monaco GP weekend is out of the way, then Sainz will need to sit down and decide what is best for both his long and short term future – and it’s a call that could well define his F1 career.
