Teenager Kimi Antonelli said Lewis Hamilton is irreplaceable after it was confirmed he will fill the British driver’s cockpit at Mercedes next year.

Hamilton’s blockbuster transfer to Ferrari leaves a vacancy at Mercedes, and, after failing to woo Max Verstappen from Red Bull, Antonelli, who turned 18 just six days ago, has been drafted in.

Team principal Toto Wolff claimed he made the decision for Antonelli to partner George Russell five minutes after Hamilton, 39 told him he would be leaving to join Ferrari in 2025.

However, Mercedes committed only to Russell and Antonelli driving from them next season, leaving the door ajar for Verstappen to be signed the following year.

Antonelli, who joined Mercedes’ junior programme when he was just 11, crashed out on his first Formula One appearance in practice for the Italian Grand Prix on Friday.

But less than 24 hours later, he was unveiled as the man tasked with taking over from Hamilton who has won six of his record-equalling seven world championships with Mercedes.

“It is not possible to replace Lewis Hamilton,” said Antonelli. “He is such a great figure in the sport today and he has achieved so much in his career.

“I don’t want to be seen as his replacement. I am just the next driver for Mercedes. He is a really great guy and he has given me some support so I am really happy with that.”

Wolff added: “Our era with Lewis started 12 years ago, and it is the longest driver-team relationship in the sport’s history. We won eight constructors’ titles and six drivers’ titles together.

“He is the biggest personality in the sport and he is the one who has beaten all the records.

“When Lewis decided to go for another challenge no-one can replace him in all of his statue, but that doesn’t mean the team is not going to prosper with two drivers that represent the future, and if we can give George and Kimi a car that can win races and championships, they can continue the legacy that Lewis leaves here.”

Wolff has admitted to exploring Verstappen’s availability in the wake of the Christian Horner scandal which rocked Red Bull and the sport.

But the Austrian continued: “I made up my mind five minutes after Lewis Hamilton told me he was going to Ferrari. Obviously we have discussed other options, and we didn’t completely discount the Max idea, looking at what happened at Red Bull. But instinctively this is the line-up that I wanted.

“Like we have done in the past, we have short contracts. This is how the team operates. They have been, and will be Mercedes drivers, and therefore we have contracts with George and Kimi that go much longer.

“They are very complicated, in terms of options, and Mercedes is a pressure cooker. It always has been here.

“But this is where we stand as a team today. We want to go with these two and we wouldn’t have gone for the line-up if we didn’t believe 100 per cent that they were the best choice for Mercedes.”

Antonelli, currently seventh in the Formula Two standings, was thrust into Russell’s cockpit in opening practice.

But his hotly-anticipated debut lasted fewer than six laps after he lost control of his Mercedes at the Parabolica at 160mph, sliding backwards through the gravel and into the tyre barrier. The impact registered at 45G and Antonelli was taken to the medical centre. He was given the all-clear to continue his F2 duties here this weekend.

“Yesterday was a mistake from my side and I learned a lesson,” added Antonelli. “I am working hard to be ready for next season. It is a dream come true and something I have wanted to happen at a young age. I cannot wait to get started.”