As Mercedes team boss Toto Wolff explained, the Briton is race-ready and knows all about the 2020 Pirelli tyres and how they perform. He also enables Mercedes to turn a negative — their star driver's sudden absence — into a potential feel-good story about a rising talent.
“George has shown impressive form this year with Williams, playing an instrumental role in their climb up the grid,” said the Austrian. “I am optimistic that he will deliver a strong performance alongside Valtteri, who will be a demanding reference for him.”
Russell will be the first driver to graduate from the Mercedes junior programme to the works team and also only the third Briton to drive for them in the Formula One world championship after Hamilton and the late Stirling Moss.
“I see this as a great chance to learn from the best outfit on the grid right now and to come back as an improved driver, with even more energy and experience to help push Williams further up the grid,” he said.
“Obviously, nobody can replace Lewis, but I'll give my all for the team in his absence from the moment I step into the car.”