Lewis Hamilton acknowledged he felt "emotional" and "surreal" after Kimi Antonelli was announced as his Mercedes replacement for the 2025 Formula 1 season.
The 18-year-old will join George Russell on the grid next year after a signing a one-year contract to fill the void left by Hamilton, who agreed a move to Ferrari at the start of the year.
Antonelli will become the third youngest F1 driver of all-time when he makes his competitive debut at the season-opener in Australia next March at 18 years and 203 days old, with only Max Verstappen and Lance Stroll younger in their first starts.
Hamilton had long been aware of the impending announcement, but admitted the reality of the situation still feels strange.
"I've known for ages, but I knew it would be announced [on Saturday]," he said. "I definitely woke up, and it was very surreal, just to have it officially confirmed my seat is going and that I've held onto it for so long," Hamilton said.
"I was quite emotional [on Saturday morning], but really happy for Kimi and for this team. I know Kimi is going to do a great job."
Hamilton will start this weekend's Italian Grand Prix sixth on the grid, while he also occupies sixth place in the Drivers' Championship having won the British Grand Prix and finished second at the Belgian Grand Prix this term.
And the seven-time world champion says he has felt a great deal of emotion heading into every race during the campaign.
"It's been there all year. Every single race, we have turned up," he added. "I love my team so much, and we have been through a hell of a lot together.
"So, it will be emotional every single race, because every race we do is the last time at that particular race and, every race, we get closer and closer to the last time I'll be in a Mercedes, and that is tough, it's definitely going to be tough.
"My focus now is to try and do the best job I can for the team and finish on a high."