GRAND BLANC, Michigan (Ticker) -- With the final major of the PGA Tour season looming, Tiger Woods and Phil Mickelson continue to make minor changes in their games.

The two top-ranked players in the world will make their final PGA Championship preparations at the Buick Open, which gets under way Thursday at Warwick Hills Golf and Country Club.

The PGA Championship will be next week at Hazeltine in Chaska, Minnesota. As always, it was a topic of conversation on the eve of the Buick Open's first round.

Woods will be playing for the first time since his quest for an unprecedented Grand Slam came to an end at the British Open. He can become the first player in history to win three majors in a season twice.

"Three of the four, and right now, myself and (Ben) Hogan are the only ones who have ever won three in the same year," said Woods, who played a practice round at Hazeltine on Tuesday. "So that would be nice to win three out of four again."

Mickelson would like just one. "Lefty" has 21 PGA Tour titles, the most of any player never to win a major. Unlike some golfers, he likes to play the week before a major, as he did here last year before finishing second at the PGA.

"It's a great practice week," said Mickelson, who has worked on his game at nearby Oakland University. "If I'm at home, I don't have that competitve environment to test myself and see what state my game is in."

Woods and Mickelson aren't the only marquee players in the field, which includes 15 of the last 19 major winners. Among them is reigning PGA champion David Toms.

"It certainly brings out the best in just about every player who is playing the tournament," said Woods, a two-time winner of the PGA Championship who represents Buick. "And I think it provides a better atmosphere for all of the fans, as well."

As usual, Woods will attract most of the fans this week, but he will need to work out some kinks in his swing, having altered it to adjust his ball flight for the British Open in windy Scotland.

"It took a few days to start feeling comfortable about letting go and making a follow-through again," said Woods, who shot a career-worst 81 in the third round at cold, wet and windy Muirfield Golf Links.

Mickelson never was in contention after the first round and tied for 66th. Continuing to work on a swing that was thrown off at the British Open, the world's second-ranked player missed the cut at last week's International.

"When I play in the wind over there, I can feel some things creep into my swing where I try to keep the ball down, keep it low," he said. "And so I have to iron those out now."

The field will be able to iron out specific shots to use at Hazeltine, with Warwick Hills offering a similar setup. Players will be able to use drivers and 3-woods to prepare for Hazeltine's distance.

"It's a great preparation because it's a similar style of golf, similar tree lines and so forth," Mickelson said.

"If it stays cool and a little bit windy like this, I think it will be the same conditions we'll see," Toms added. "And I think this will be a nice tune-up."

It should at least be a good show for the fans. Warwick has been extremely birdie-friendly in the past, yielding a winning score of 15-under par or better each year since 1993.

Last year, Kenny Perry missed the tournament record by a stroke, finishing at 25-under 263.

"If you're not on your game and playing great, you're not going to win this tournament," said Woods, who has yet to win at Warwick Hills. Because you've got to shoot almost 20-under par."