Vettel won all four of his world titles during his six-season stint at Red Bull between 2009 and 2014 before joining Ferrari for 2015.
Ferrari opted against renewing Vettel’s contract when it expired at the end of the 2020 season, paving the way for the German driver to switch to Aston Martin for the following year.
Vettel was linked with a potential return to Red Bull and it was known he had spoken to its F1 advisor, Helmut Marko. But Red Bull team principal Christian Horner ruled it out as a viable option during the summer of 2020.
The team ultimately turned to Sergio Perez - who became a free agent when Aston Martin decided to sign Vettel – when it opted to replace Alex Albon at the end of the 2020 season.
Vettel was asked by Motorsport.com at Monza about the seriousness of talks with Red Bull following his Ferrari exit, but he said it was never a firm prospect.
“I made the decision to join Aston Martin before I think it was really in discussion that Alex is going to leave,” said Vettel.
“So it was never really close. But of course, I know, Christian, I know Helmut. So for sure, I had a brief chat with them, but never really anything serious.
“And I also knew that if it was, if it would have been an option or serious, we would have at least talked about it. But it never came to that point.
“So obviously, a couple of months later, you could look back and say what if, and so on. But I'm happy with the choice I made.”
Vettel will retire from F1 at the end of the season, leaving Aston Martin after two years that have seen him score its best result since rebranding for 2021 with second place in Azerbaijan last year. 2022 has proven more difficult for Aston Martin, but Vettel said there were no regrets about his decision to join the team.
“We expected that we will be more competitive last year and this year, but we were not,” said Vettel.
“I’m very happy with the way the team has progressed and [how] we are working together. So obviously it's not the dream coming true, racing in the positions we are racing, but it's been a challenge.
“I think I've accepted it and tried to make the most of it.”
Vettel has not yet confirmed any post-F1 plans besides appearing in the Race of Champions in January, and said he was currently “not considering anything” that would retain any ties to the F1 paddock, such as a non-driving role.
“Time will tell what will be something that is possible to do, if there is an offer of any such nature or not,” he said.
“Then I will see how I feel. At the moment, I’m quite happy to spend more time on other things and look forward to seeing the kids more and stuff like that.
“Then time will tell whether I get bored within three months or three years. I don't know. So we will see.”