Red Bull boss Christian Horner says the reigning F1 champions have been kicking themselves for missing out on an opportunity to sign Australian driver Oscar Piastri.
Piastri will join the F1 grid next season after he was signed by McLaren to replace fellow Aussie Daniel Ricciardo, whose own future in the sport remains cloudy.
The former F2 and F3 champion's junior career had been backed by Alpine before Piastri was snagged for F1 by McLaren, however Horner says Red Bull actually had a chance to sign him themselves.
Horner said he regretted not signing Piastri to Red Bull ahead of his F3 campaign in 2020.
Piastri had been working his way up to F3 with Arden Motorsport, a team founded by Horner and his father competing in the lower motorsport classes.
Despite getting a close look at the Australian's abilities, Horner and Red Bull looked elsewhere for junior talent, a decision the team principal now regrets.
He told the F1 Beyond the Grid podcast that while he would have loved the chance to see Piastri in Red Bull colours, the Australian rookie would have a lot to prove next season.
"There was an opportunity for Red Bull to look at him at the time and we didn't take up that option, which is something that I regret," Horner said.
"The only problem he now has to deal with is (that) the expectation on him will be immense," Horner said.
"He's going to have to get in and deliver against Lando, which is no mean feat.
"But you either sink or swim in this business. He's a very, very capable driver, I'm sure he's going to do very well."
Piastri eventually made his way to McLaren after a contract dispute with Alpine, who had publicly announced him as their replacement after Fernando Alonso announced an abrupt switch to Aston Martin for next season.
Alpine have worn criticism for their handling of negotiations with Alonso and Piastri, having let a two-time world champion and one of the sport's rising stars leave the team.
Australian F2 driver Jack Doohan in mix for Alpine F1 seat
Jack Doohan, son of five-times motorcycle world champion Mick, is a contender to replace Fernando Alonso at the Renault-owned Alpine Formula One team, according to chief executive Laurent Rossi.
The 19-year-old is doing well in his rookie Formula Two championship season and is a member of the Alpine driver academy.
Rossi told the www.formula1.com website that Doohan was a consideration, even if fourth-placed Alpine would prefer someone more experienced who would be able to score big points immediately.
"We believe in him, he's shown a lot of potential, especially lately - talk about being present at the right moment," Rossi said.
"He's a great person, he is fast, his father is also a champion I admire and a person I admire. One way or another we will try and put him in an F1 car at some point."
Mick Doohan was 500cc world champion, before that class became MotoGP, from 1994-98.
Rossi said, however, that Alpine were "once bitten, twice shy" after the recent contract dispute with Australian reserve driver and 2021 Formula Two champion Oscar Piastri who has signed for McLaren for 2023.
Alpine had spent heavily on preparing Piastri and had planned to loan him to Williams, in the same way Mercedes did with George Russell.
"We will honour our commitment to all drivers in our academy, but we're wondering whether or not to continue," said Rossi.
"We are torn apart. We believe in the value of the system but if we're not protected, is it worth it?
"We really wonder. It's a big disappointment. Perhaps a big reality check."
Experienced French driver and race winner Pierre Gasly is seen as Alpine's first choice to replace double world champion Fernando Alonso, who is moving to Aston Martin next year, alongside Esteban Ocon.
Click here to sign up to our newsletter for all the latest and breaking stories from Australia and around the world.