LOS ANGELES — One of Jason Day’s goals at the start of the year was to stay at No. 1 for the entire calendar year. The year is not even two months old, and already he is facing his first big challenge.

And not just from one player.

Dustin Johnson, coming off a third-place finish at Pebble Beach, and Phoenix Open champion Hideki Matsuyama both have a mathematical chance to reach No. 1 in the world by winning the Genesis Open at Riviera. Johnson would need Day to finish around fourth or worse, while Matsuyama could reach the top only by winning with Day finishing about 25th or worse.

Tiger Woods in 2009 was the last player to start and finish a year at No. 1.

Rory McIlroy was the last player to stay at No. 1 for longer than a year, starting with his victory at the 2014 Bridgestone Invitational and ending when Jordan Spieth passed him with a runner-up finish in the 2015 PGA Championship.

Just don’t get the idea Day is consumed with the ranking.

“I said earlier that a calendar year would be great to go No. 1, but I need to just focus on what I need to do because you can’t really focus on staying No. 1,” Day said. “The more you focus on the actual target itself, the more you attach yourself to it, you make mental errors out there, you get more frustrated, you do silly things on the golf course that you shouldn’t be doing.”

Johnson also had a mathematical chance to get to No. 1 last week, but he would have had to win Pebble and have Day finish out of the top 50.

Day tied for fifth. Johnson also had a chance at the PGA Championship last summer, but he missed the cut and Day was runner-up.

Day doesn’t have a lot of history at Riviera. The only reason he is playing is because of the tour’s new “strength of field” regulation that requires most players to compete at an event they haven’t been to in four years.

John Daly has thrown golf clubs during fits of frustration over the course of his wild career. He says his putter going into a lake at a PGA Tour Champions event last week was not one of them.

“If I throw a putter, it’s going to be in two pieces, not one,” Daly said Wednesday. “And it’s going to be 50 yards in the lake, not 5.”

Daly said reports of his throwing his putter into the lake at the Allianz Championship in Boca Raton, Florida, were lacking context.

The two-time major champion said his sciatic nerve was acting up and he probably shouldn’t have played. He decided to withdraw after the seventh hole and while walking off the green, he flipped the putter over his shoulder to his caddie, who wasn’t watching, and the club went into the water.

There was no video of the incident. A writer for linksmagazine.com posted a photo on Twitter of the top of Daly’s putter in the water as fans gathered around for a look.

“I take responsibility,” Daly said. “I shouldn’t have tossed it.”

He was more distraught at losing the putter, which he described as a 50-year anniversary model of the Ping Answer that company chairman John Solheim gave him. Daly said he called the head pro at The Old Course at Broken Sound to see if he could get it back, but someone had already retrieved it.

Daly’s most recent club throw was at Whistling Straits at the 2015 PGA Championship, when he put three balls in the water on the par-3 seventh hole and after hitting the green on the fourth try, he slung his 6-iron into Lake Michigan.

“That was a proper throw,” he said.

BACK SPASMS not only kept Tiger Woods from playing at Riviera, they forced him to withdraw from a news conference.

Woods, the unofficial host of the Genesis Open, pushed his news conference back to Wednesday and then canceled it. The tournament said in a statement that after getting daily treatment the last four days, Woods was advised by doctors to limit all activities.

Even talking?

“He flew out here and got to see one of his doctors,” Mark Steinberg, his agent, said Wednesday. “Based on the work they did the last couple of days, they advised he just stay horizontal. It’s best to listen to the doctors. The ultimate goal is to get out and play.”

Woods has not played Riviera, his hometown event, since 2006. When California-based Hyundai Motor America signed on as title sponsor last year, it picked the Tiger Woods Foundation as the chief charitable beneficiary and host organization.

That assured Woods would play, and even after back spasms surfaced in Dubai two weeks ago, he still flew to California on Saturday with hopes of taking part in tournament activities. Instead, he has stayed in his hotel.