In an interview this week, Vettel admitted that he was aware that he wouldn't be in F1 for very much longer and that what he will do next "is something you naturally start to think about". He suggested he might be interested in moving on to other forms of motorsport.
But if Vettel has already started to mentally let go of what he called the "spoiled circus" of F1, then what's to keep him hanging around when his current contract Ferrari expires at the end of the year? He's said himself that money isn't a factor in his decision and that's very easy to believe - but if he's no longer as committed to the sport as he was as a teenager, why keep going at all? A step down to a midfield team seems rather pointless, although you'll have to ask fellow former champions Alonso, Raikkonen and Damon Hill whether they feel such an investment proved ultimately worthwhile.
A return to Red Bull (with whom he's remained on good terms) could be an option - the team is still seeking a driver who can go toe-to-toe with the previous Verstappen - but that would mean Vettel exchanging one mortal threat in the form of Leclerc for another and once again running the risk of being the de factor number two driver. Ten years ago the challenge would have galvanised Vettel - remember his rivalry with Mark Webber during his championship winning run? - but will be vastly less appealing to him now.
The coronavirus shutdown could prove to be a trial run on what Vettel's life would be like without Formula 1 in it
Whether he does, it's hard to see any scenario which lands Vettel a fifth world championship, or equalling Schumacher's record levels of success now under seige by Hamilton. So what's the target keeping Vettel motivated race after race, month after month, season after season? It's why I expected Vettel to announce his retirement at the end of 2019 or during the winter break. When that didn't happen there was a brief flurry of revived retirement speculation when Vettel called a press conference at the start of pre-season testing in Barcelona, but Vettel is far too professional and decent to destabilise his team by walking out so close to the start of a new campaign.
So what will the effect of the indefinite delay (or even cancellation) of the 2020 season have on Vettel? It's certainly given him plenty of time to sit and mull his decision, and to discuss it with family and friends. It could even be a trial run of what his life would be like without Formula 1 in it.
Maybe that will make him fully realise what he will be missing if he does decide to retire - but equally, maybe he'll find that he's at a stage in his life when staying at home, playing with the kids and fulfilling his dream of studying for a degree in mechanical engineering is all he wants and needs. After all his past success and achievements in motor sport, it would be hard to blame Vettel if he did choose to hang up his helmet and start a new chapter in his life, at a time when F1 itself is also at a crossroads.
The current shutdown means Vettel doesn't have the opportunity to reaffirm his talent on track in the new SF1000 - or equally, face the risk of any further unfortunate mishaps. But it may allow his bosses at Ferrari to view his undoubted strengths with a little more distance and clarity than during the white heat of competition. If so, Mattia Binotto may yet conclude that Vettel is still key to Ferrari's fortunes - and make him an offer he can't refuse for 2021.