Lewis Hamilton unsurprised by Nico Rosberg's retirement

"I'm probably one of the only people that it was not a surprise to."

Lewis Hamilton insists he is not surprised that his long-running rival Nico Rosberg has brought the curtain down on his Formula One career.

World champion Rosberg, 31, stunned the sporting world on Friday after he announced his decision to retire from grand prix racing just five days after clinching his maiden title.