Alpine has confirmed Franco Colapinto will replace Jack Doohan for the next five races, starting at Imola's Emilia Romagna Grand Prix.
On Wednesday, the French team announced it had taken the novel decision to "rotate" the driver in its second race seat alongside Pierre Gasly.
Colapinto's position will therefore be reevaluated ahead of the British Grand Prix in July, leaving the door open for a possible Doohan return.
"Having reviewed the opening races of the season, we have come to the decision to put Franco in the car alongside Pierre for the next five races," Alpine executive advisor Flavio Briatore said. "With the field being so closely matched this year, and with a competitive car, which the team has drastically improved in the past 12 months, we are in a position where we see the need to rotate our line-up.
"We also know the 2026 season will be an important one for the team and having a complete and fair assessment of the drivers this season is the right thing to do in order to maximise our ambitions next year.
"We continue to support Jack at the team, as he has acted in a very professional manner in his role as a race driver so far this season. The next five races will give us an opportunity to try something different and after this time period we will assess our options."
Doohan's position has been in doubt since Alpine signed Colapinto to a reserve driver role in January.
The Argentine vaulted to prominence by impressing as Logan Sargeant's replacement at Williams for nine races last year.
Williams loaned him to Alpine this year with an expectation he would get some race experience.
"Firstly, I want to thank the team for giving me the opportunity to drive competitively for the next five races," Colapinto said. "I will work hard with the team to prepare for the next race in Imola and the upcoming triple-header, which will no doubt be intense and a big challenge for everyone.
"I have stayed sharp, and I am as ready as possible with the team's race support testing programme, as well as on the simulator at Enstone. I will do my best to get up to speed quickly and give it my all to deliver the best possible results alongside Pierre."
Doohan struggled to make a mark in his five races this year, crashing on numerous occasions and struggling to match the qualifying performances or race results of teammate Pierre Gasly.
"I am very proud to have achieved my lifelong ambition to be a professional Formula One driver and I will forever be grateful to the team for helping me achieve this dream," Doohan said. "Obviously, this latest chapter is a tough one for me to take because, as a professional driver, naturally I want to be racing.
"That said, I appreciate the team's trust and commitment. We have long-term goals as a team to achieve and I will continue to give my maximum efforts in any way I can to help achieve those.
"For now, I will keep my head down, keep working hard, watch with interest the next five races and keep chasing my own personal goals."
On Tuesday, Alpine confirmed team principal Oliver Oakes has resigned with immediate effect, with Briatore taking over Oakes' duties.
Oakes had said as recently as the Friday at the Miami Grand Prix that, at that moment, the plan was to keep Doohan alongside Gasly for the next round in Imola.