NAPA, United States (AFP) - Third-ranked Rory McIlroy, still leading the European Tour's Race to Dubai with six weeks remaining in the campaign, launches his bid for a 2015-16 US PGA Tour crown on Thursday.

The new American season tees off just 18 days after the Tour Championship ended the old one as McIlroy, a four-time Major champion, and England's seventh-ranked Justin Rose, the 2013 US Open winner, top the names at the Frys.com Open.

"I'm happy to be here and to get a bit of a start," McIlroy said on Wednesday. "It seems like any time I come back to the PGA Tour in February, guys have played eight or 10 events and I'm trying to play catch-up. I want to get my season off to a good start."

Many of McIlroy's top rivals are resting now. Jordan Spieth, who won the Masters and US Open, and Jason Day, who captured his first major at the PGA Championship in August, will wait to begin their 2015-16 campaigns.

"If you look over the course of the last 12 months, yeah, they have won more than I have, more Majors sure. I think that's an accurate representation," McIlroy said.

"I want to win tournaments again. Seeing them win Majors, doing something I've done before and want to do again, that gives me motivation. I want to get my game back to the level where it has been and can be again."

Seeing Spieth and Day fight for titles and top ranking has made golf fans excited for 2016 although McIlroy warned that Americans Ricky Fowler and Dustin Johnson are among those fighting to join the rivalry at the top.