The current state of Formula 1 amid the coronavirus pandemic "won't work in the long term", according to Red Bull official Dr Helmut Marko.
An unnamed team boss was recently quoted as saying that another full year of 'ghost races', quarantining and social distancing could bankrupt teams.
"The fact that we were able to put together a calendar at all in 2020 is very positive," Marko told Kronen Zeitung.
"But the empty paddock where you see all these people with masks is also frustrating from an emotional point of view.
"Atmospherically and also financially, it won't work in the long term," the Austrian warned. "The economy won't be able to make ends meet if things continue like this."
Williams is currently missing its acting team boss and several other team members in Istanbul amid a covid outbreak.
Mercedes chief Toto Wolff admits he is concerned that the last race in Abu Dhabi is being held just a little over a week before Christmas.
"We don't want even one of our team members to have to be quarantined in the desert for Christmas," he said. "I think we'll have to fly everyone out in a charter plane."
