And no sooner had Sainz been announced as a Ferrari driver, came the news that Renault driver Daniel Ricciardo would replace Sainz at McLaren.
That was a surprise, given Ricciardo had mystified the F1 paddock with his move from Red Bull to Renault at the end of 2018 because he needed a new challenge. With no podium finishes last year, and having witnessed the Renault-powered McLaren team beat Renault to fourth place, or "best of the rest" in the Constructors' championship, Ricciardo has obviously decided his move to Renault wasn't a wise one.
All these drivers' moves have of course come before a wheel has turned at an F1 race since the first scheduled race in Australia as part of a 21-race calendar, was cancelled at the 11th hour.
Nobody knows for sure how any of the cars may perform should the season ever get under way, so it is surprising the "silly season" for driver movements has started before this one has even started.
The catalyst for Vettel leaving Ferrari has come from the team favouring newcomer Leclerc by offering him a three-year extension on his contract after one season, albeit a very successful one, that netted him two race victories, including the prestigious Italian GP at Monza, seven pole positions, and 4th place in the drivers' championship, one place ahead of Vettel.
By contrast, only recently was a contract extension offered for Vettel, reportedly a one-year extension with his remuneration substantially reduced from the $40 million plus bonuses he is believed to be receiving. Last week those negotiations fell through. "My relationship with Scuderia Ferrari will finish at the end of 2020," Vettel announced. "To get the best possible results in this sport, it's vital for all parties to work in perfect harmony. The team and I have realised that there is no longer a common desire to stay together beyond the end of this season. Financial matters have played no part in this joint decision. That's not the way I think when it comes to making certain choices and it never will be."
Vettel also revealed the coronavirus pandemic has led to "many of us reflecting on what are our real priorities in life". He says he wants to finish his long stint with Ferrari - this being his sixth year - by adding to the moments they have enjoyed together.
Ferrari boss Mattia Binotto said the joint decision was for the best, but "not an easy decision to reach, given Sebastian's worth as a driver and a person".
"Sebastian is already part of the Scuderia's history, with his 14 Grands Prix wins making him the third most successful driver for the team, while he is also the one who has scored the most points with us."
Michael Schumacher, with 75 wins and five drivers' titles, is Ferrari's most successful driver by far. Alberto Ascari and Niki Lauda, with 15 victories and two titles each with Ferrari, surpass Vettel's record to date.
Should the German win a race this season, he will equal Ascari and Lauda for wins, but a championship with Ferrari will elude him unless he can beat Hamilton and his hungry-for-success teammate, Leclerc, should there be eight races this year, which would constitute a championship.
Sainz is being portrayed as the number two to Leclerc, but 2009 world champion Jenson Button, has questioned that thinking.
"If Mattia Binotto has gone for Carlos because he thinks he is a good pair of hands and won't give Charles a run for his money then I think he is mistaken," Button says.
"I think Carlos is a winner like his father, he wants to go out there and do the best he can and wants to bring home a championship. He's chosen the wrong person if he just wants a good atmosphere within the team. He's obviously a great character but he wants to win."
Button also says it is weird time, given F1 cars have been on the track in months, to be making driver choices, when drivers are not driving.
Should Vettel remain in F1, his choices are limited. Toto Wolff says it would be great "marketing gimmick" to have a German in a German team. But Hamilton is unlikely to go anywhere, and Valtteri Bottas will hope to impress the team this year and retain his drive.
Waiting in the wings is George Russell, a Mercedes driver currently on loan to Williams, which has meant he can't show his real talent, but beating teammate Robert Kubica 21/0 in qualifying last year gives some indication of his true ability.
Former driver David Coulthard thinks it would be a mistake to put Vettel alongside Hamilton.
"In Lewis, you've got someone who can win grands prix and championships. To bring Seb in there because you think that that will raise Lewis' game…it's very difficult.
"I think Vettel could be disruptive to the team."
Ricciardo's move to McLaren leaves a vacancy at Renault, but it didn't take long for the Spanish press to proclaim a certain Fernando Alonso might be up for a third stint with the team with whom he won the championship in 2005 and 2006. It was speculated that F1 owners Liberty Media might help Renault to pay for Alonso's services, given he was earning $30m at McLaren when he left F1 at the end of 2018.
But McLaren boss Zak Brown, who will be helping Alonso try to win the Indy 500 for his team should that race be held this year, has cast doubt on whether Alonso has the appetite to take on the F1 challenge again.
"I spoke to him the other day, I was snooping around, and I think he is undecided," Brown told Sky Sports."If I was running Renault, I am clear that's who I would put in the car. He's a great name, fast as anybody. He won two championships with them, so he has history. From Renault's perspective, I think it's pretty obvious who to put in."
But he questioned if Alonso wants to return to 22 races with a car that does not seem capable of winning yet.
"Given that they've on a similar journey back to the front - and I think that they'll get there, they're a great team, great resources, great company that's been there, done that before - I don't know if Fernando has the appetite to be on a three-year journey versus getting in a car he can win in in 2021."
Alonso's manager, Flavio Briatore says "Fernando is motivated. A year out of Formula 1 has done him good. He has detoxed himself and I see him more serene and ready to return."
A similar scenario would apply to Vettel. Joining Renault must be an option, but he may prefer to take a sabbatical for one year. Alain Prost fell out with Ferrari at the end of the 1991 season and sat out 1992, before returning with Williams in 1993 and securing a fourth title, and then retiring for good.
Vettel is only 32, three years younger than Hamilton, so despite this being his 14th year in F1, he is far from finished with the sport.
But two-time world champion Mika Hakkinen wonders if Vettel will be able to maintain the high energy levels needed to stay at the top of the sport.
"Sebastian has a big decision to make about his future," Hakkinen stated.
"He was not considering retirement, but he will now have to look at what other options are available in 2021 and 2022, as well as consider how he feels about the job of remaining a Formula 1 driver - especially if he is unable to drive for a winning team."
Sky Sports commentator Martin Brundle says Vettel was talking to at least one other team and he's got to have a chance at Renault, a works team.
"But you'd worry going into the future," Brundle suggested.
"Renault will be lone rangers, they'll be the only people using Renault engines as of 2021."