Magnussen was absent from the track on Friday after beginning to feel unwell on Thursday.
Oliver Bearman was promoted in his place, the Brit taking part in opening practice and Sprint Qualifying.
That necessitated his participation in Saturday’s Sprint at a minimum, leaving Magnussen to return only for qualifying in a best-case scenario.
“MoneyGram Haas F1 Team driver Kevin Magnussen will not participate in Friday’s track running at the São Paulo Grand Prix after suffering with sickness,” the squad initially announced.
“Official reserve driver Oliver Bearman will take over driving duties.”
However, following Sprint Qualifying, it was confirmed Magnussen would miss the entirety of the event.
“Following Ollie stepping into the VF-24 for today’s sessions due to Kevin’s sickness, we can confirm that the British driver will now complete the full #BrazilGP weekend with the team,” it announced.
“We wish Kevin a full and speedy recovery.”
Bearman progressed through to the final phase of Sprint Qualifying, where his lap time was deleted for exceeding track limits at Turn 4.
That will see him start Saturday morning’s race from 10th, two places ahead of team-mate Nico Hulkenberg.
Sunday’s race will be the third of Bearman’s career, having replaced Carlos Sainz at Ferrari when the Spaniard suffered appendicitis in Saudi Arabia.
He then raced for Haas in Azerbaijan when Magnussen served a one-race ban.
The 19-year-old will join the team full-time next season when he will partner Esteban Ocon.
The Sao Paulo GP Sprint begins at 11:00 on Saturday (01:00 AEDT Sunday) ahead of qualifying for the grand prix itself starting four hours later.
