Ralf Schumacher has rejected suggestions Mercedes may actually stick with Valtteri Bottas for next year.
The former Formula 1 driver thinks it is obvious that the German outfit will actually move the young and highly-rated George Russell from Williams for 2022 and beyond.
"I am firmly assuming that Russell will be in the Mercedes next year," Schumacher told Sport1. "Anything else would be completely incomprehensible for the future.
"Lewis is 36, so in another two or three years, the cheese will already have been eaten," the former Williams driver added.
"Mercedes has to prepare for the time after Lewis, and Max Verstappen is no longer an issue for them."
However, Bottas said last weekend that Hamilton has told him "directly" that he would prefer if the 31-year-old Finn remains on the team next year.
Schumacher thinks 23-year-old Russell would definitely give Hamilton a push.
"Russell will put more pressure on Lewis," he said. "What he did in Bahrain last year was unbelievable.
"George didn't even fit in the car because of his size, but he still would have won if the team hadn't of made that mistake at the pitstop.
"That was a great achievement by him. Lewis knows that too which is why he came back very quickly for Abu Dhabi," Schumacher added.
