Kevin Magnussen has rejoined Haas to replace Nikita Mazepin.
The Danish driver returns to F1 and rejoins the team which he left at the end of the 2020 season.
Magnussen was replaced by Mazepin who was heavily backed by father Dmitry, owner of title sponsor Uralkali.
But after Russia invaded Ukraine to widespread condemnation from world leaders, the team removed the blue and red livery along with the sponsor's logos for the final day of the first pre-season test.
F1 acted swiftly to cancel the Russian Grand Prix before Haas terminated its contracts with the Mazepins at the end of last week.
It was expected Pietro Fittipaldi would join Mick Schumacher for the season, with the Brazilian having filled in for Romain Grosjean at the end of 2020 and being named for the Bahrain pre-season test this week.
But Magnussen has returned to the sport despite holding existing contracts with Chip Ganassi Racing in IMSA and a factory Peugeot drive in WEC.
“I’m delighted to welcome Kevin Magnussen back to Haas F1 Team,” commented team principal Guenther Steiner.
"When looking for a driver who could bring value to the team, not to mention a wealth of Formula 1 experience, Kevin was a straightforward decision for us.
"Kevin’s immediate availability means we can tap into him as a resource for pre-season testing alongside both Mick Schumacher and Pietro Fittipaldi.
"Pietro’s going to be first in this week with half a day’s running at the test on Thursday - that’s a great opportunity for him, with Mick and Kevin doing the rest ahead of the Bahrain Grand Prix.”
Magnussen added: “I was obviously very surprised but equally very excited to receive the call from Haas.
“I was looking in a different direction regarding my commitments for 2022 but the opportunity to return to compete in Formula 1, and with a team I know extremely well, was simply too appealing.
"I really have to say thank you to both Peugeot and Chip Ganassi Racing for releasing me promptly – both are great organizations.
“Naturally, I also want to thank Gene Haas and Guenther Steiner for the chance to resume my Formula 1 career – I know just how competitive they both are and how keen they are to return to competing week in and week out.
"I’ve been briefed as much as possible on the development of the VF-22 and the potential in the package. There’s work to do but I’m excited to be a part of it. I can’t wait to get back behind the wheel of a Formula 1 car in Bahrain.”