Piastri sits 36 points clear of Guanyu Zhou - who was announced at Alfa Romeo on Tuesday morning - in the F2 standings with just two rounds remaining.

Alpine has already retained Fernando Alonso for next year, while Esteban Ocon signed a new long-term deal earlier in the season, keeping him at the team until 2024.

Piastri replaces Daniil Kvyat as the team’s reserve driver, and he will undertake “an extensive testing programme” during the year.

The Australian has an impressive junior career, winning the Formula Renault Eurocup title in 2019 and taking the Formula 3 title a year later in his rookie year.

Piastri is on the cusp of the F2 title after taking three wins, seven podiums and three pole positions in 2021.

“I’m super excited to be joining Alpine F1 Team as Reserve Driver,” he said. “I’m looking forward to being much more involved with the team and contributing to its intended success next season.

“The reserve driver role is the next step towards my aim for a race seat in 2023, which is very exciting. I’ve proved myself in the junior formulas over the last couple of years and feel like I’m ready for Formula 1 now.

“Along with the trackside experience at race weekends, we will put together a substantial test programme in order to keep developing myself to grow even more prepared for a race seat.”

Alpine CEO Laurent Rossi added: “Oscar’s natural talent is clear to see, so we’re very proud and privileged to have him as part of our team as our Reserve Driver from next year. 

“Not only does Oscar have the on-track skills, as demonstrated over the last couple of years in the junior categories, but also the maturity and composure that makes him really stand out from the rest. At Enstone he has been a real asset to the team as he has aided the simulator and testing programme and I am certain he will continue to do so in his new role. 

“The next step will be to consistently attend Grands Prix to fully integrate with the race team, learn what is expected of an F1 driver and be ready for when the opportunity comes. In addition, we look forward to having Oscar’s input and expertise in driving the team forwards next year.”