Esteban Ocon says he could not race in Abu Dhabi last weekend because of his height.
When George Russell had his undisclosed personal issues at the 2019 finale, Williams reached out to Mercedes' reserve driver, Frenchman Ocon.
"George was sick and I was the only one who could replace him," Ocon, who is preparing for his first Renault test in Abu Dhabi this week, told Le Figaro.
"But I could not get into the car. It was clearly not possible," said the Frenchman, who is 186 centimetres tall.
Ocon says his height is an issue in Formula 1, but the situation should improve for 2021.
"The width of the cockpits will remain the same but there will be more space in the length," he said. "That's good news."