World champion Rosberg, 31, stunned the sporting world by announcing his decision to retire from grand prix racing just five days after clinching his maiden title.
But Hamilton, who has been competing against Rosberg ever since their formative racing years in karting, has claimed he was not taken aback by his Mercedes team-mate’s decision.
“I’m probably one of the only people that it was not a surprise to,” Hamilton, who was in Vienna alongside Rosberg at FIA’s end-of-season prize-giving ceremony, said.
“This is the first time he’s won a title in 18 years, hence why it was not a surprise that he decided to stop.
“He’s also got a family to focus on, and wants more children, and Formula One takes so much of your time. Will I miss the rivalry? Of course.”
Rosberg, who only signed a two-year extension to his Mercedes contract in July, made the shock revelation in Vienna as he prepared to receive his champion’s trophy.
The German initially informed only a handful of people — including Hamilton — of his stunning decision, before revealing he first pondered retirement after he took control of the championship battle with victory at October’s Japanese Grand Prix.
He becomes the first reigning Formula One champion to retire from the sport since Alain Prost in 1993, and revealed he is now looking forward to the next chapter of his life with wife Vivian, and their one-year-old daughter Alaia.
“Since 25 years in racing, it has been my dream, my ‘one thing’ to become Formula One World Champion,” Rosberg, who started his career with Williams in 2006, said in a statement on Facebook.
“Through the hard work, the pain, the sacrifices, this has been my target. And now I’ve made it. I have climbed my mountain, I am on the peak, so this feels right.
“My strongest emotion right now is deep gratitude to everybody who supported me to make that dream happen.”
Rosberg emulated his father Keke, the 1982 world champion, after he crossed the line in second place following a tense season finale in Abu Dhabi last Sunday.
Rosberg’s jaw-dropping move leaves Mercedes, Formula One’s all-conquering team who have won 51 of the last 59 races, with a vacancy for 2017. At this stage, it is unclear who they will choose to partner Hamilton, who insists he is not bothered who joins him.
“It doesn’t matter who they pick,” Hamilton, 31, added. “I’ll race them, and I’m here to race. Now the focus is obviously on next year and hoping for a better season.
“As long we’re treated fairly, it doesn’t matter who is alongside you. Of course, we’ve got great team bosses who I’m sure will choose the right people to be representing the brand.”
Ferrari’s Sebastian Vettel, a winner of four titles, and McLaren driver Fernando Alonso, a double world champion, have been mooted as potential mouth-watering contenders.
Both drivers, however, are under contract with their respective teams for next season.
Pascal Wehrlein, the 22-year-old German, who is a member of the Mercedes young driver programme, is also in the frame.
“He has deputised for both Hamilton and Rosberg in testing.
“I’m interested to see who would want to be my team-mate, and respect anyone that would want to,” Hamilton, the triple world champion, added.