The 23-year-old Italian goes into the race at the Nelson Piquet Circuit with an 89-point lead over Japanese team-mate Tohru Ukawa.

"I can win the world championship in Rio and I will try to do so because it will be more fun for my friends than Motegi," Rossi said after winning the rain-soaked Portuguese Grand Prix.

"Seriously though, the important thing is to win the title, it doesn't matter where."

Japan's Motegi round follows Brazil before races in Malaysia, Australia and a season finale in Valencia but Rossi should sew up the title sooner rather than later.

Rossi has already won motorcycling's 125, 250 and 500cc titles and has won on each of his last four visits to Rio.

With 25 points on offer for the winner, Rossi will clinch the title if he wins and Ukawa fails to finish in the top three.

The Honda rider has dominated the season, winning nine of the 11 races, and also won last year's Brazilian Grand Prix by which time he had already won the title.

One more win would make him only the second rider, along with compatriot Giacomo Agostini, in the history of the sport to have had 10 victories in successive seasons in the top class.

Ukawa, who won his first 500cc race in South Africa this year, has finished third in the last three races.

He started last year's race in Brazil in pole position.