Sebastian Vettel has revealed he once held talks with Niki Lauda over a potential switch to Mercedes to partner Lewis Hamilton.
The four-time champion will leave F1 after this weekend's Abu Dhabi Grand Prix after collecting 53 wins and 122 podiums.
Vettel's stint with Red Bull from 2009 to 2014 was the most fruitful, challenging for the title in his first year before securing four in a row between 2010 and 2013, the last of which was thoroughly dominant as he took nine successive victories.
A move to Ferrari in an attempt to replicate his hero, Michael Schumacher, in turning the ship around at the Scuderia showed glimpses of greatness but ultimately fell short, before his final two years with Aston Martin.
But after driving for two of the top three teams of his generation, Vettel was asked on the 'Beyond the Grid' podcast whether there had been an opportunity to sign for Mercedes.
"I don't know, maybe there was," he replied. "I spoke with Niki [then-Mercedes non-executive chairman].
"But to be honest, I was halfway through the Ferrari period and joining would have been a big deal because Lewis was their number one and I am not sure they would have liked to have had us both in the team.
"I also didn't have a great interest at the time because I was so committed to Ferrari and that was my dream, to make that thing work.
"So you talk to each other but it wasn't like really serious."
On whether he would have relished going up against then-championship rival Hamilton, Vettel insisted: "Yeah, I think it would have been a great challenge and I would have enjoyed that.
"It wasn't meant to be.
"At that time, my focus was to win with Ferrari. That was my target. I didn't want to change team and win with Mercedes.
"Other than winning, which I really love, it was winning with Ferrari that was the great goal. It just didn't happen and that is fine.
"I would have enjoyed racing with Lewis, we get on really well."