Lewis Hamilton says “it could take a long time” before Mercedes can compete again with Red Bull.
Mercedes have started a process of redesigning their car having started a second consecutive season off the pace.
But the seven-time champion said: “It is going to take us the rest of the year to potentially close that gap.”
His team-mate George Russell added: “I am not going to say we are terribly optimistic. We recognise Red Bull are a second down the road at the moment.”
Red Bull have dominated the start of the season, taking two one-two finishes in the first two races, and are clear favourites again at this weekend’s Australian Grand Prix in Melbourne.
Briton Hamilton said: “If you look at the Red Bull, it is just going to continue to evolve most likely.
“Some cars do plateau in terms of performance. At some point it can’t just keep going. But maybe it can.
“They have a great team around them and I am sure they will continue to add downforce.
“We just have to make sure when we do make the change hopefully the drop isn’t too far and hopefully it is going to take us the rest of the year for sure to potentially close that gap.”
Hamilton opened up on his struggles with the Mercedes car and how he feels uncomfortable with the positioning of the cockpit.
He said: “I don’t know if people know, but we sit closer to the front wheels than all the other drivers. Our cockpit is too close to the front.
“When you’re driving, you feel like you’re sitting on the front wheels, which is one of the worst feelings to feel when you’re driving a car.
“If you were driving your car at home and you pulled the wheels right underneath your legs, you would not be happy when you’re approaching the roundabout.
“What that does is it really changes the attitude of the car and how you perceive its movement. And it makes it harder to predict compared to when you’re further back and sitting more centred. It is just something I have really struggled with.”
The 38-year-old also expanded on comments he made after the first race of the season in which he said the engineers “didn’t listen” to him with regard to the design of this year’s car.
“I listened to the team and that was the direction they said we should go,” he said. “Had I known the feeling I would have in it, it wouldn’t have happened. And it has to change for the future – 100%.”
He added that a characteristic referred to in F1 as the “aero balance” – a reference to the centre of aerodynamic pressure and how it affects the car’s behaviour changes through the stages of cornering – was “just too far forwards”.
“We have a car that is very forward, very much on the nose early on, and then shifts later on,” Hamilton said.
But he expressed his belief that Mercedes would get back into competitive shape eventually.
The first significant design changes to the Mercedes car are due for the race after Australia, in Azerbaijan at the end of April.
However, these were planned before Mercedes made the decision during the first race weekend of the season that they had to change the design philosophy of the car because the gap to Red Bull made them realise they were on the wrong track.
