By Mark Lamport-Stokes
(Reuters) - This week's PGA Championship in Louisville, Kentucky is likely to deliver further confirmation that a new world order is establishing itself in the game with players such as Rory McIlroy and Adam Scott now leading the way.
While Tiger Woods, Phil Mickelson, Ernie Els and Vijay Singh have been golf's dominant figures over the past two decades, the present and immediate future appears to belong to McIlroy, Scott, Bubba Watson, Martin Kaymer and other 'young guns'.
Masters champion Watson and U.S. Open winner Kaymer have each won two majors while in-form McIlroy, who clinched his third at the British Open last month in wire-to-wire fashion, will be aiming for a career grand slam at next year's Masters.
Australian world number two Scott landed his first major championship crown at the 2013 Masters and ever since has been a perennial contender in golf's blue riband events, recording four top-10s in his last six starts.
As Scott prepares for the year's final major, the PGA Championship at Valhalla Golf Club beginning on Thursday, he is well aware of a gradual 'changing of the guard' at the game's highest level.
"There are these first-time winners, a change of the best players in the game ... some new faces, guys winning their first major and now guys winning their second or third, establishing the greatest players of this era of the game now," said Scott.
"That's probably what we're seeing. We'll be looking back and talking about Bubba and Martin and Rory in the future, much like we spoke of Ernie, Phil, and Tiger, Vijay, Retief (Goosen) and (Padraig) Harrington.
"There weren't that many guys out here with multiple majors for a while. I think we're getting to another level of the game now where we're seeing the new era of great players."
The PGA Championship has often been the most unpredictable of the four majors, in part because it attracts the strongest field, and this week is no different with 99 of the world's top 100 players entered to compete at Valhalla.
Long-hitting American Dustin Johnson will not be there while he takes an indefinite leave of absence from golf to seek help for "personal challenges" and there is also some doubt over the participation of former world number one Woods.
Four-time PGA champion Woods, who had surgery in late March to treat a pinched nerve in his back, pulled out of the WGC-Bridgestone Invitational on Sunday following a back spasm and is expected to make a decision about Valhalla over the coming days.
Woods, a 14-times major winner, has not triumphed at the highest level since the 2008 U.S. Open and has been a shadow of the player he once was while contending with assorted injuries, swing changes and problems in his personal life.
'GLORY'S LAST SHOT'
With or without Woods, a host of contenders will be competing for "glory's last shot" in the season's final major.
"(Course) set-up also plays a big part in it," Scott said during last week's WGC-Bridgestone Invitational in Akron, Ohio.
"If it is soft, it can favor someone, but it can help others as well. You've just got to play well ... if any of the top 25 guys is really on, their standard of golf is very good."
There is a chance of thunderstorms in Louisville on Wednesday and Thursday and Scott believes a rain-softened Valhalla layout, with more receptive greens, will lengthen the list of potential winners.
"However deep you want to go, if anyone plays well around a course that's softer and scorable, there's that opportunity for them because greens will receive shots from all distances," said the Australian, who tied for fifth at last year's PGA Championship.
"You're just going to have to be on your game. But purely looking at the strength of field, it (the PGA Championship) is the hardest to win."
Newly crowned world number one McIlroy, who romped to victory by a record eight shots in the 2012 PGA Championship at Kiawah Island, heads to Valhalla with his game in sparkling form.
He became the third youngest player in the modern era, after Jack Nicklaus and Woods, to win three of the four majors with his triumph in last month's British Open at Hoylake, then won the Bridgestone Invitational on Sunday in his next start.
Those successes have made the 25-year-old Northern Irishman even hungrier to rack up further accomplishments.
"There's a lot of big tournaments left this year, a lot of golf left to play and a lot of things I still want to achieve," said McIlroy. "I feel like I've got a lot of momentum.
"Hopefully ride that, play some really good golf and some golf similar to what you saw at Hoylake."
Valhalla, carved out of sandy hills and ringed in bluegrass, is a par-71 layout measuring 7,458 yards off the back tees and will be staging its third PGA championship. Mark Brooks triumphed in 1996 and Woods won the 2000 edition.
Other likely contenders this week include 2010 champion Kaymer of Germany, Spanish world number three Sergio Garcia, fourth-ranked Swede Henrik Stenson and last year's U.S. Open winner Justin Rose of England.
(Reporting by Mark Lamport-Stokes in Los Angeles; Editing by Gene Cherry)