Kevin Magnussen has withdrawn from Friday's running at the Sao Paulo Grand Prix because of illness and will be replaced at Haas by reserve driver Oliver Bearman.
The US-based team announced the swap on Friday before first practice at the Interlagos circuit.
The move means Briton Bearman will take part in Friday's sprint qualifying session and the shorter sprint race on Saturday.
A spokesperson for Haas said it was "too early" to know whether Magnussen would have recovered in time to take part in qualifying for the grand prix itself later on Saturday.
It will be Bearman's second competitive appearance for Haas in five grands prix after the 19-year-old replaced Magnussen when the Dane was banned from the Azerbaijan Grand Prix in September for accruing too many penalty points on his licence.
Bearman, who will race for Haas in 2025, scored a point in Baku with a 10th-placed finish.