Dr Helmut Marko says preparations for Formula 1's return to racing next month are "going like clockwork".
"Now all we have to do is keep calm," the Red Bull official, who has been the leading figure in organising the first 'ghost races' of the coronavirus era, told f1-insider.com.
Amid face masks and other health protocols, Mercedes' two drivers shook out the rust with tests at Silverstone this week, and Racing Point is set to follow suit next week.
Ferrari is also heading to Fiorano with a similarly two-year-old car.
Marko says the 2020 season will be particularly intense.
"Since you don't know how many races there will be in the end, every one of them is of course even more important now, almost like a kind of endgame," he said.
"So reliability will be the key to winning the world championship. Any failure could cost you the title, including driver mistakes, of course," added Marko.
"We are expecting a duel between us and Mercedes. In our opinion, Ferrari is not at the level of the frontrunners."
