After the 21-year-old Aussie gained attention for securing back-to-back title wins in Formula 3 and Formula 2, Horner labelled the missed opportunity, “something that I regret”.
Speaking on F1’s Beyond the Grid podcast, Horner said it was “difficult” to discuss Piastri’s controversial signing with McLaren but agreed had he been in Red Bull’s system – a move that could have happened – his place in the team would have been tightly secured.
READ MORE: Fagan ‘doesn’t recall’ key Hawks accusation
“He drove for Arden (the junior team founded by Horner) in Formula 4 and Formula Renault, and was obviously a significant talent,” he said.
“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. But what he went on to achieve is phenomenal, in Formula 3 and Formula 2.
“Now if he’d have been a driver here, there is no way that he wouldn’t have been under lock and key for a period of time. As I say, I wasn’t party, it’s difficult to judge what was promised or reneged on or so on.
“But certainly, it was unexpected, probably from several areas.”
The Melburnian raced for Arden Motorsport in the British F4 Championships and Formula Renault Eurocup as a teenager before joining Renault’s driver development academy (now Alpine Academy) at the start of 2020.
According to Horner, the aftereffects of Fernando Alonso’s move to Aston Martin “created the ripple that rolled out over numerous seats”, including that of Red Bull’s sister team, AlphaTauri.
After losing the contract case to keep Piastri, there were reports that Alpine intended to bag Pierre Gasly, however AlphaTauri will only release the Frenchman from his one-year contract extension if it has a replacement already lined up, such as IndyCar driver Colton Herta.
But AlphaTauri’s plan to have Herta line up on the F1 grid next season is contingent on the Andretti Autosport driver receiving an exemption from the FIA for an obligatory superlicense which so far has been refused.
Test and reserve driver Nyck de Vries has also emerged as a candidate for the seat after his successful points finish in the place of Alex Albon at the Italian Grand Prix.
While Red Bull is not considering any of its existing young drivers for the drive, in a similar move to Yuki Tsunoda being elevated in 2021, Horner feels its program is still in good shape.
“We’re continuing to invest in youth, we’ve got some great youngsters in the program, all the way from karting and stepping into Formula 4 now, upwards,” he said.
“I think it’s something Red Bull has done so well, giving these kids a chance, investing in young talent, and giving opportunities they otherwise wouldn’t have had.
“Isack Hadjar in Formula 3 this year has had a great debut season. I think [Ayumu] Iwasa in Formula 2 has been a standout driver for me. They’re just two of the guys on the program.
“Liam Lawson has had a tough year, but he’s again another talent. Dennis Hauger has been a bit underwhelming in Formula 2 after such a dominant year in Formula 3. But again, how much of that is him and how much of it is the equipment?”
But with 19-year-old rising star Jack Doohan also departing the Red Bull Junior Team after five years at the start of 2022, could the UK-based team’s emerging talent be drying up?
For a daily dose of the best of the breaking news and exclusive content from Wide World of Sports, subscribe to our newsletter by clicking here!