After nine weeks atop the world golf rankings, including five this season, Jason Day has no grand illusions about how long he might be able to stay there.

For Day, who is as unpretentious as they come, it’s one week at a time.

The 28-year-old Australian checks the updated rankings each Monday to see where he comes in, then quietly goes back to working on his game regardless of where he stands among the top players globally.

“It’s good to be No. 1,” Day said Tuesday before his practice round for the Zurich Classic of New Orleans. “I know I’m at nine weeks now (for his career), and I just want to get to 10. After that, I want to get to 11; and after, that I want to get to 12; and so on and so on.”

Day chuckled at the mere thought of a text message he received earlier this season from Greg Norman, a fellow Aussie, regarding Day’s most recent ascent to the top of the rankings five weeks ago.

“He said that he would love to see me pass him,” Day said. “I’m like, ‘Uh, that’s 330-something (actually 331) weeks at No. 1.’

“That’s a very dominant career in my mind, and if I have the opportunity to do that, I know it’s going to take a lot of sacrifice and dedication. It’s great to be at the top of your game, to be No. 1, but it’s more so to be motivated than ever before to try to extend that lead.”

That will be the task this week at the Zurich Classic, where Day on Thursday will become the first No. 1-ranked player in the world to participate in the New Orleans event since David Duval in 1999. Duval missed the cut by two strokes after rounds of 70 and 74.

Day is hoping his good play continues at TPC Louisiana, where he returned a year ago after a six-year absence and tied for fourth at 19-under. He held the lead at the midway point of the tournament and shared the third-round lead with eventual champion Justin Rose.

Day, who won five times on the PGA Tour last season, has two more victories this year and has won six of his past 13 starts. One of those wins was his first major at the PGA Championship.

But his recent success and No. 1 ranking has only made him hungrier.

Getting to the top of the rankings, he said, was the toughest part.

“Climbing that mountain is very difficult,” he admitted. “Having to go through a lot of failures to get to this point is difficult, but you learn the most when you fail.

“That’s the biggest thing you’ve got to understand: When you’re trying to improve something, if you fail, it’s OK. You have to learn from it and get better for the next tournament.”

Day comes to New Orleans refreshed, as he took last week off after playing four tournaments in five weeks — a grind that also included an extra week in Augusta, Georgia, to prepare for the Masters.

He tied for 10th at the Masters, then finished in a tie for 23rd at the RBC Heritage before spending a week at home with his wife, Ellie, and their two children.

Day decided to come back to New Orleans again because it fits in well with his schedule. He’ll bypass the Wells Fargo Championship next week to get ready for The Players Championship.

“I’ve played in a lot of tournaments in a row before, and it’s just not a good formula for me,” said Day, one of only two players on the PGA Tour to win twice this season. “I was a little tired (after the RBC Heritage).

“On top of that, there were some certain things — some bad habits — that had kind of crept into my game. When you’re playing a lot, you don’t get to practice. … You don’t have time to work some of those kinks out.”

Some quality time on the range as well as work around the chipping and putting greens have Day ready to go.

“I feel pretty good about my game right now,” he said. “I’m very pleased with where I’m at mentally and physically. So from there on, I’ve just got to try to make sure I stick to the game plan, stay focused on trying to win the event, and hopefully the rest takes care of itself.”

Follow Sheldon Mickles on Twitter, @MicklesAdvocate.