Hamilton is the hardest worker, says Russell

British rookie George Russell has reminded anyone expecting otherwise that his compatriot Lewis Hamilton's talent and unrivalled work ethic have made him Formula One's most complete driver.

On the eve of this weekend's Russian Grand Prix, and after three straight Ferrari triumphs, the highly-rated Williams driver's message will warn Ferrari fans not to expect Hamilton to ease off while defending his lead in the title race.

Russell, who worked with Hamilton while he was at Mercedes as a junior driver, said he had studied the defending five-time champion at close quarters and been amazed at his work rate.

"He's the most complete driver that I've ever, ever come across," said the young Englishman. "Just with the details and everything, it's exceptional. He doesn't just rely on natural talent to be quick.

"He goes into every single detail to try and be better and better. He's one of the most hardworking people I think I've come across in the paddock -- which I think shocks a lot of people."