Haas has confirmed Russia's Nikita Mazepin will race for the team in 2021, with a similar announcement about Mick Schumacher expected later this week.
Mazepin and Schumacher, the son of seven-time Formula One champion Michael, are replacing Romain Grosjean and Kevin Magnussen, who both look set to leave F1.
Mazepin, backed by billionaire father Dimitry, is in his second season of Formula Two. He has completed extensive private testing in old Mercedes F1 cars in preparation for his rookie season.
The Mazepin news was announced the same day Grosjean is due to be discharged from hospital following a miraculous escape from a huge crash at Sunday's Bahrain Grand Prix. Grosjean sustained burns to both hands in that crash and will miss this Sunday's Sakhir Grand Prix as a result.
His place will be taken by Brazil's Pietro Fittipaldi, with Mazepin and Schumacher tied up with the F2 season finale in Bahrain, which takes place over the same weekend as F1's Sakhir GP.
If Grosjean is unable to contest the final race of the F1 calendar, the Abu Dhabi Grand Prix on Dec. 13, Mazepin and Schumacher would be candidates to make an early debut.