It will be almost "impossible" for F1 to replace Charlie Whiting.
Whiting, the sport's long-serving FIA race director and starter, died suddenly in his Melbourne hotel room on Wednesday night.
His deputy, Michael Masi, has been named as his replacement for now.
But 1996 world champion Damon Hill said Whiting, who was 66, will be "extremely difficult if not impossible to replace".
Valtteri Bottas confirmed that Whiting was "very important" for the sport and the drivers.
"If we had concerns about anything, like the curbs or the marshals or anything, he always reacted. He had a huge impact on formula one," said the Mercedes driver.
"At the moment it's hard to imagine who can do all of this instead of Charlie, but I am sure there will soon be a plan."
Gunther Steiner, the Haas team boss, confirmed that F1 has a "structure" in place that will take over Whiting's duties.
"Whatever the FIA decides this weekend, the teams will support it," he said. "We can do little to help, but we can do that.
"It will take some time for the Federation to restructure everything, but this weekend, if we can help with something, we definitely will."
