Red Bull's drivers have revealed their concern about car reliability.
After two races in 2023, it seems almost certain that this year's fight for the world championship will be between two drivers only - Max Verstappen and Sergio Perez.
At Jeddah, Perez won from pole - but arguably only because Verstappen's driveshaft failed in qualifying.
So while the situation suited the Mexican in Saudi Arabia, Perez is worried similar trouble might affect his Red Bull sooner or later.
"It's going to hit us at some point," he said. "Even in Bahrain, if we had to push to the end, we probably would have made it. So there are a lot of reliability concerns at the moment.
"We've had a lot of mechanical issues."
In Saudi Arabia, too, those on the Red Bull pitwall were furiously trying to control the drivers' pace at the front of the race.
"The biggest moment of concern was when Max told us he heard a loud noise. We immediately started thinking about the driveshaft problem from the day before," said team boss Christian Horner.
Perez says he also felt "strange vibrations" during the Saudi race.
"Obviously what happened to Max was in the back of my mind and I'm sure the back of the mind of the team as well," he said.
So far, the concerns have not stopped Red Bull from achieving a perfect record of two consecutive 1-2 finishes.
"The whole feeling in the team, everyone is happy," said world champion Verstappen. "But personally, I'm not happy.
"I'm not here to be second and when it looks like it's going to just be between two cars, we have to make sure that the two cars are reliable."
Even Frederic Vasseur, the new Ferrari team boss, thinks it could be reliability that ultimately determines whether Verstappen or Perez wins the title.
"Imagine now that Perez wins two more races and Verstappen retires - a gearbox fails and he gets a penalty for the next one," said the Frenchman.
"After Monaco, Perez is then 100 points ahead of Verstappen. These situations can happen - don't forget the season with Rosberg and Hamilton," Vasseur added, referring to 2016.
"Nobody expected Nico to win that world championship and then he did."
