Hamilton is moving to Ferrari and Mercedes' protege Antonelli is a candidate to take the seven-times world champion's place alongside George Russell (26) despite his lack of experience.

Asked at the Emilia Romagna Grand Prix how Antonelli's recent test in an older car had gone, Allison said the engineers had spoken highly of the youngster who is currently competing in Formula Two.

"Just a young, enthusiastic driver, very, very fast, metronomic in his pace. Has not been in an F1 car until recently, but made it look like he'd been in one for ages within a lap or two," said Allison.

"He came at this generation of cars, the ground effect cars, with an open mind. Yeah, he feels all the same things that you'd expect him to feel. But he's not sort of polluted by the previous cars.

"So he just takes them as they are and tells us what he is feeling as weaknesses and strengths. And lets the engineers work to try to improve those things. But he looks like a very promising young driver."

Hamilton said on Thursday he would take a gamble on the Italian, if it were his call.

"Honestly, I have no idea what (team boss) Toto (Wolff)'s plans are but I think, for me, taking on a youngster would be...if it was my job, if it was my role...I’d probably take on Kimi," he said.

Hamilton made his Formula One debut at McLaren in 2007 at the age of 22, the most successful driver in the history of the sport finishing on the podium in his first race in Australia.

Red Bull's triple world champion Max Verstappen debuted at the age of 17 in 2015.