Haas boss Gunther Steiner says Kevin Magnussen will be well enough to qualify for the Mexican grand prix on Saturday.
On Friday, the FIA excused the Danish driver from the mandatory driver briefing due to a "medical condition".
It is believed Magnussen is unwell with a stomach complaint and must be cleared by FIA doctors to return to his car on Saturday.
"I don’t think it affected him too much," Steiner told Ekstra Bladet newspaper.
"I think there was a time when he had to leave the car because he needed something, but otherwise he was well enough.
"But we and (Magnussen’s trainer) Thomas (Jorgensen) suggested that he should go back to the hotel instead of the driver meeting.
"He’ll be fine," Steiner added.
"He was actually ok when he left, but my point of view was that he should not infect anyone else."
When asked if Magnussen will be well enough to drive on Saturday, Steiner answered: "Yes, yes."