Nico Rosberg has been fuelled by the pain of watching team-mate Lewis Hamilton claim another Formula One world championship title in 2015, says Damon Hill.

The German has finished runner-up to his fellow Mercedes driver for the past two seasons, but leads by 23 points ahead of this weekend's Japanese Grand Prix.

Hamilton sealed his third career crown by overhauling pole-sitter Rosberg to win the United States Grand Prix in October last year - an event that Hill believes provided the latter with a much-needed spur.

"If he wins the championship I think it will be thoroughly deserved," Hill, the 1996 world champion, told Sky Sports F1. "He's really worked hard.

"Since the pain in defeat in Austin we all saw a changed person in Nico. He went on to win all the remaining races and he's put up a very strong challenge this year.

"Some of his drives have been impeccable."

Mercedes need 21 points to seal the constructors' title on Sunday, having been left in the unfamiliar position of seeing Red Bull take the top two podium spots in Malaysia last time out.