Brian Keogh in Los Angeles

Star power has been turned on full wattage for the Northern Trust Open with 17 of the game’s top 20 players set to do battle over the fabled Riviera Country Club course in the heart of Hollywood fantasy land.

Yet even with the distractions of near neighbours David Beckham and Britney Spears, an absentee Tiger Woods has managed to cast his long shadow over the the PGA Tour event where world No 2 Phil Mickelson and Open champion Padraig Harrington are joined by European Ryder Cup stalwarts Lee Westwood, Justin Rose and Luke Donald.

Even defending champion Charles Howell III, who is a close friend of the world number one, confessed that while a tournament without the Tiger-factor gives everyone a better chance, something is missing.

"You always want to beat him and win an event that he's in," said Howell, who beat Mickelson after a three-hole play-off last year. "Like it or not, he is the guy that moves the needle the most. He is our biggest star.

"On the flipside, when he doesn't play you know, his winning percentage is pretty high these days, so it does free that up a little bit."

Woods has yet to win at Riviera in 11 tries, though Howell added: "Tiger is too competitive to go through his career without a win at Riviera. I would think he would want it on his resume. Just his competitiveness would want it there."

Howell is staying with a relative on the same street as Beckham and Spears. He knows because he saw the paparazzi outside when he stayed there last year.

"I figured Tiger Woods lost his ball over there," Howell joked. "And I come to find out it was David Beckham."

The Woods-factor has been dubbed ‘Woodsitis’ in the case of Ernie Els, who along with Henrik Stenson, is the other major absentee from the strongest field in world golf so far this season.

The South African was the talk of the range yesterday following reports from WGC-Accenture Match Play executive director Michael Garten that he is "strongly considering" playing in Arizona next week after all.

Yet Howell can understand the pressure that Els feels when he faces Woods, having been fingered as one the hotshots that was going to rival Woods but has won just twice in five seasons.

For 28-year-old Augusta native Howell, the public has always been fascinated with who might step up to challenge Woods: "They are so desperate for a guy to challenge Tiger Woods. That adds to the hype of a rookie every year: Who is going to be the guy?

"Tiger always talks about winning, and how winning handles everything. A guy who is going to challenge Tiger on a consistent basis is going to have to win a lot.

"With the depth of the fields, you have to remember that if you throw Tiger Woods out of the way, Phil Mickelson is the greatest golfer we've ever seen besides Jack Nicklaus.

"If Phil isn't there, you look at Vijay Singh; look at all the tournaments he's won in his 40s. People today and the media today is so impatient that they want great results from you yesterday.

"Sergio García, he's a failure. Really? The guy's had a hell of a career, but in a lot of people's eyes, he hasn't won a major, so he needs to hang it up and quit."

Padraig Harrington is one of a handful of players who have taken on Woods in his pomp and beaten him. But he doesn’t agree that it is any tougher now for the chasing bunch than it was back in the 1980s

"Look, it was even tougher for the guys back in the 80s when there were even more great players around," said Harrington, who has been battling the effects of a head cold since Sunday. "What was it like when you had Faldo, Norman, Seve, Lyle and Woosie and all those guys?"

Reasonably pleased with his share of 14th place at Pebble Beach last week, Harrington is focussed on getting his game in shape for the Masters in April as well as fine-tuning a swing change.

"This is a two-month programme to get myself ready for the Masters and last week at Pebble Beach was reminder of all the stuff I have done over the winter and where it has got me," Harrington said.

"There is a distinct difference between technical practice and tournament play and it showed up last week. I wasn't tournament sharp.

"What I am trying to do is hold the ball off in flight. It is a lower spinning shot, held off, with a straighter flight - a bit like the way Monty played.

"If I had six months to go away and work on it, it would all be fine. But the fact that I have to play golf now interferes a little bit with that. But I am happy enough with the way things are going."