When Sergio Perez lines up on the grid in Bahrain next month, it will be the first time the Austrian team has recruited outside the ranks of its young driver programme since Mark Webber was lured from Williams at the end of 2006 to partner David Coulthard, who had joined from McLaren just two years earlier.
The Scot was subsequently replaced by Sebastian Vettel - following a brief stint with BMW-Williams - and since then the Austrian team has never looked beyond the talent pool that is the Helmut Marko-led driver programme.
With Alex Albon not providing the back-up for Max Verstappen that the team required, Red Bull was forced to look elsewhere, and by chance Sergio Perez was free after being dropped by Racing Point in favour of Vettel.
"It was a tremendously difficult decision," Christian Horner tells Motorsport.com, "and one that we were fortunate to have time to be able to fully consider. The whole season in fact.
"It's highly unusual for a driver of Sergio's quality and ability to be on the market," he admits. "So, we just felt that we would be better placed putting in a more experienced driver alongside Max as we head into 2021.
"I think it was a grown-up view that we took to go outside of the scheme. And to give Sergio a chance. Obviously he drove so well last year, particularly in the in the last third of the season.
"He's got ten years’ worth of Formula 1 experience," the Briton continues, "I think he's demonstrated his ability to maximise the Pirelli tyre. And, of course, he just brings a whole host of experience, of the podiums that he's achieved and results that he's achieved in cars that have, until last year, been far from competitive.
"I've known Sergio a long time, he drove for my team in GP2 years ago, and I've always followed his career with interest. It was just a matter of circumstances that presented itself as an opportunity and made sense for Sergio to take the seat alongside Max this year."