The seven-time world champion’s prediction came after he finished more than a minute behind Red Bull’s Max Verstappen, who claimed a record-extending 17th win from 20 races this season at the Sao Paulo Grand Prix.
Hamilton slipped to eighth in Sunday’s race at Interlagos, while teammate George Russell retired from 11th, on what was Mercedes’ worst performance of a challenging 2023 campaign.
“Ultimately, all I can do is try to remain optimistic,” Hamilton, whose contract runs until the end of 2025, said.
“But the Red Bull is so far away that they are probably going to be very clear for the next couple of years.”
Hamilton believes Mercedes’ new floor was not working correctly in Brazil and said it had pushed the team into an incorrect set-up that had inadvertently resulted in their unusually excessive tyre usage.
“My guess is that the floor is not working,” he said.
“It’s not sucking down and it’s pushed us to go to a higher wing, and then we’re just massively draggy on the straights and sliding in the corner. We have to look into why that is the case on this rough circuit.
"The tyres were overheating slow on the straights, no grip in the corners.”
The result leaves Hamilton 32 points adrift of Red Bull’s Sergio Perez, who finished fourth, denting the Briton’s hopes of claiming second place in the championship.