George Russell - who lives in Oxford - will start just the 10th grand prix of his life on Sunday.
The 21-year-old is entering the Silverstone race as an F1 driver for the first time.
Russell signed to the Mercedes' junior programme in 2017, shadowing Hamilton for two years, before team principal Toto Wolff engineered the youngster's move to Grove-based Williams.
Originally from Norfolk, he has left team-mate Robert Kubica, a driver Hamilton rated as the outstanding rival of his generation before the Pole's devastating rally crash in 2011, firmly in his shade.
Russell heads into the British Grand Prix with a perfect 9-0 record in qualifying and unbeaten in the races.
He said: "If Toto called me tomorrow and asked if I was ready to drive for Mercedes my answer would be absolutely.
"I am not going to rely on Valtteri having bad races. I am going to go out there and make it happen for myself. If that is not good enough then I will hold my hands up and say I didn't do the job.
"I am on top of my game. Right now, I am 100 per cent dedicated to Williams, but if Mercedes called me up, I will be ready."
Russell arrived in F1 with a fine CV, winning the sport's two feeder championships in successive seasons.
"I don't like to think about chance," he continues. "Mercedes have given me targets. Each time, I have met them, and they have rewarded me. I have faith that if I have performed to the right level, there is no reason why I will not get the opportunity.
"You only have to look at what Max Verstappen and Charles Leclerc have done at Red Bull and Ferrari. You can argue about experience all you want, but sometimes it is not all you need."
Russell lives in a one-bed flat in Oxford, 15 miles from Williams' Grove headquarters, and is dating Seychelle De Vries, the Dutch sister of Formula Two championship leader Nyck.
He added: "If you look at top CEOs, their schedules are down to the minute, and that is how you have to look at a Formula One driver," he says.
"I wasn't prepared for the intensity of a grand prix weekend - you don't have a minute to breathe.
"One day, I forgot to tell the team what time to get my lunch ready. I'd finished my media duties but I had nothing prepared to eat, so I had to have a curry with the boys. It was just unnecessary stress.
"Even on the grid, we are interviewed just before we go out and do our job. Can you imagine Rafael Nadal or Roger Federer walking out 10 minutes before they start on Centre Court being asked how they are feeling?
"You are more than just a driver, you are representing a brand. If you asked what my ideal weekend would be, I would like to arrive an hour before, jump in the car, go racing, and then go home, sit on my sofa and drink a glass of champagne.
"But I understand F1 wouldn't survive like that. I recognised that from a young age, and that is why I have tried to excel in all areas."