Morikawa tries to overtake Rahm for No. 1 in Hawaii

World number two Morikawa, the reigning British Open champion, is among 38 players who will begin play in 2022 at Kapalua's 7,596-yard Plantation Course.

The 24-year-old American will take the top spot with a victory unless Rahm finishes alone in second. Morikawa could finish as low as third and still topple the Spaniard for number one.

"It has been a dream my entire life to get to number one in the world, but it's not just about getting to number one. It's about sustaining that," said Morikawa.

"Having the opportunity here, it's all in my control. All I can do is try and win the tournament and that's all I'm going to focus on.

"But it's a huge goal. It always has been and it means something that when you do get there it means you're doing something right or at least a good amount of things right."

Morikawa has been making plenty of correct moves since making his pro debut in June 2019, starting with his first PGA triumph the following month at the Barracuda Championship.

In 2020, Morikawa won the PGA Championship in only his second major start, a final-round 64 making him the third-youngest winner of the event.

Last year, he captured the Claret Jug at Royal St. George's, becoming the first player to win two different majors in his debut and the first player since Bobby Jones in 1926 to win two major titles in eight starts or fewer.

In November, Morikawa won the DP World Tour Championship, becoming the first American to capture the Race to Dubai.

Now he has achieved a career high in the rankings with only one higher spot to climb. Even so, Morikawa says that would bring new challenges.

"It's just about continuing that process," he said. "It's not like that's a peak, I get to number one and I can go retire and relax on the beach. There are still so much things that I'm going to keep pushing myself if or when that does happen."

- Rahm ready for challenge -

Reigning US Open champion Rahm has a similar philosophy about the top spot even as he clings to it.

"I'm number one because of how I played in the past, so if I want to stay here, I got to keep playing at the level and trying to get better," Rahm said Tuesday.

"I try to improve my game and improve my level of golf. If I can do that and play the way I know I can play, everything else should take care of itself.

"I'm not thinking constantly, 'He's number two,' or 'He's coming for me,' I need to do this or that. I'm trying to play the best that I can and hopefully win a tournament."

Morikawa will be without green reading books under a new rules change.

"It's huge," he said. "I used them a lot for my approach shots... so it's going to be an adjustment."