Williams hopes a physical problem with Logan Sargeant will be resolved once the American rookie hits the new Las Vegas track late on Thursday.
The 22-year-old, whose race seat is the only one on the current Formula 1 grid still unconfirmed for 2024, had to retire from the ultra-hot Qatar GP recently with dehydration.
"I hadn’t been feeling well all week, so that certainly didn’t help," Sargeant is quoted by Speed Week. "I was extremely reluctant to bring the car into the pits because I didn’t want to let my team down.
"But I just couldn’t do it anymore."
Sargeant then had another major physical problem at Interlagos, when he told his engineers that he completely lost feeling in a paralysed left arm.
Team boss James Vowles says Sargeant has recovered for Las Vegas.
"We think it was his seat," he said. "It’s the first time this has happened this season, so it must have had something to do with the Interlagos track, which is anti-clockwise.
"We’ve done some detail work on the position of the seat belts and the seat."
Vowles insisted: "We believe the problem will not reoccur in Las Vegas."