LOS ANGELES (AP) -- Steve Stricker has a new appreciation for the lengths some players go to compete on the PGA Tour.
Stricker, the defending champion at the Northern Trust Open, is fresh off the longest trip of his life. He flew halfway around the world to in the Qatar Masters and it felt like his first day at school. He didn't know where to register. He never got caught up on his sleep. There was more to that week than playing golf.
2011 NORTHERN TRUST OPEN
The Northern Trust Open boasts the strongest field of the season so far.
The collection of players at Riviera this week include Louis Oosthuizen of South Africa, Padraig Harrington of Ireland and Ryo Ishikawa, the 19-year-old from Japan.
"I don't know how they do it," Stricker said. "I found it very hard to go over there and concentrate and play well. And I can see when these guys travel across from Europe to here how difficult it's got to be for them."
The travel is what makes Riviera so intriguing this week.
It marks the PGA Tour debut this year of Oosthuizen, the British Open champion who joined the U.S. tour for the first time. Another rookie is Robert Karlsson, a 41-year-old from Sweden who recently moved from Monaco to Charlotte, N.C. There's also Ishikawa and K.T. Kim of South Korea, both ranked inside the top 50 in the world.
The world will be coming to America for the next several months, and while none of the top three players in the world are at the Northern Trust Open -- Lee Westwood, Martin Kaymer and Tiger Woods -- this very well could be the strongest field so far this year.
Riviera has five of the top 10 in the world, and 16 of the top 30.
From last year's PGA Tour money list, only three players are missing from the top 20 -- Ernie Els, Tim Clark and Camilo Villegas, all of whom are not here because of nagging injuries.
Next week is the Match Play Championship in Arizona for the top 64 in the world. Two weeks later is another World Golf Championship event at Doral, with more tournaments in Florida and Houston as players get ready for the Masters.
There are different starting lines in golf.
PGA Tour members tend to begin their season in Hawaii. The European Tour essentially kicks off in the United Arab Emirates. But there is a sense at Riviera, with so much depth to the field, that the best are starting to congregate.
"When I played in Hawaii, it almost felt like the silly season," Hunter Mahan said. "Some guys were just done playing Chevron, or playing in China. San Diego was a little more of a normal routine. But it doesn't seem like an event is a real event until all the international guys start showing up."
Phil Mickelson is another headliner at Riviera, where he will try to win for the third time on a course that used to give him fits. And just like Ishikawa and Oosthuizen, he had to get on a plane to get here.
OK, so Mickelson didn't have that far to fly.
As he often does, Mickelson has found it easier to stay at home with his wife and three kids in San Diego and fly his jet up the coast to Santa Monica. Door-to-door it takes him about an hour, which is how long it can take to just get down Sunset Boulevard when leaving Riviera at the wrong time.
Mickelson had a slightly tougher time Wednesday, with such low cloud cover that he was forced to land in Van Nuys, adding a half-hour to his flight. He's not losing any sleep over that one.
"I'm a little concerned the next day or two getting in with some of the low minimums of the clouds," Mickelson said. "It looks like it's going to be OK."
As for his game? Mickelson isn't worried about that, either.
He was energized going into this year, with his health improved and his wife's battle with cancer having turned the corner. Mickelson just hasn't been getting the results, except for a runner-up finish at Torrey Pines. He has won twice at Riviera, and hopes to make this the sixth tournament he has won at least three times.
"I've been playing well," he said. "I've got just a slight hurdle to get over where I've got to get the scores down to how I feel I'm playing. Some of that will be course management, some of that will just be getting a couple putts to drop, but I feel like I'm right on the cusp of playing some really good golf."
Weather could be a factor beyond Mickelson's flight plan.
It was cool, windy and rainy for the pro-am, and the forecast is for rain during various parts of the week. That hasn't affected the course too much, as Riviera was in such great shape that it can hold water and still remain relatively fast.
Karlsson didn't have to travel as far as he once did to get here.
With his two children getting older, and life too cramped in a small apartment in Monaco, Karlsson figured it was time to move on. One option was Sweden. But his runner-up finish in Memphis last year paved the way for him to earn a PGA Tour card, and he decided it was time to take up membership in America.
Why not move to Florida? Karlsson wanted a change of seasons, and he met enough people in Charlotte that he was hooked. Although it was cold enough in the south this year that he didn't get much time to work on his golf.
"With the winter being quite harsh in North Carolina -- not for a Swede, but for golf -- I was hoping to get a bit of practice in," he said. "And it didn't work out that way."
He had two top 10s in the Arabian desert, so it's not all bad.