EUGENE, Ore. — For the first time since 1999, the World Championships of Track and Field will go on without Bryan Clay.

An aching left hamstring muscle sent the Olympic decathlon champion, out of Castle High School and California's Azusa Pacific University, to the sidelines at the USA Track and Field Championships yesterday.

And without a 1, 2 or 3 finish at these Nationals, there was no way for Clay to claim a place on the American team heading for the Worlds, which open Aug. 15 in Berlin.

Clay was out before the Nationals decathlon ever started. After a few, slow early morning steps on the warmup track at the University of Oregon's Hayward Field, the 29-year-old recognized as the "World's Greatest Athlete" — on the Wheaties box and by track enthusiasts the world over — realized "there was no way I can do this.

"I felt a few little pops in my hamstring (in a low-key warmup here Tuesday)," said the subdued Clay. "It didn't feel like anything too serious. I got back on the (long jump) runway and tried to give it another try, when I realized it was a little worse than I thought."

An array of physical therapy maneuvers — from acupuncture to intense massage to medication — failed to relieve the pain.

After huddling with his coaches and advisors, Clay reluctantly announced his withdrawal.

The empty lane six in the second section of the decathlon 100 meters — the lane Clay was scheduled to occupy — said it all.

The event went on without him and propelled Trey Hardee, a 25-year-old Mississippi State graduate who came to Eugene with the 2009 world decathlon lead — with his 8,516-point score at the Gotzis, Austria meet last month — as the hot favorite to take the overall crown as well as the decathlon gold medal in Berlin.

His 2009 World Championships ambitions crushed, Clay will spend weeks in rehab and start planning what he can do the rest of the year.

A major target may turn out to be the September decathlon in Talence, France — the same event that Dan O'Brien used as his world-record vehicle after bombing out of the 1992 USA Olympic Trials.

Only O'Brien (8,891 points in 1992) has ever scored better among Americans. And Czech great Roman Seberle's 9,026-point score in 2001 remains within reach for Clay.

Before the meet, Clay cited recent improvements in at least half the decathlon's 10 event as optimism-laced expectations of challenging the Seberle and O'Brien marks.

But as this sport's often cruel history has shown, the line between an athlete's world-class condition and a place on the injury list is often a fine one.

When Clay is fully on his game, he's generally unbeatable. Three of his greatest performances came in winning gold medals at the 2005 World Championships in Helsinki (8,732 points), the 2008 USA Olympic Trials in Eugene (his all-time best 8,832) and the 2008 Beijing Olympic Games (8,791).

But he's had a number of major disappointments, as well.

Injuries forced him out of finishing all 10 events at the World Championships of 2001, 2003 and 2007, along with the USA Nationals of 2006 and 2007.

And now the 2009 Nationals can be added to the list.

Clay's long-range targets, however, remain in place.

He's determined to be the first American decathlete to medal in three Olympic Games (he placed second at Athens in 2004 before winning it all in Beijing.)

He's determined to get fully healthy and not let these nagging injury problems erase his ambitions.

And he's determined to return the decathlon to major prominence. He didn't get any of the mega-star treatment after Beijing that such American predecessors O'Brien (Athens 1996), Bruce Jenner (Montreal 1976), Bill Toomey (Mexico City 1968), Rafer Johnson (Rome 1960), Milt Campbell (Melbourne 1956) or Bob Mathias (London 1948 and Helsinki 1952) earned after their gold medal performances.

"Our goal is to bring the decathlon back to life in the U.S.," said Clay. "And we have the athletes we know can do just that."

And he's determined to acquire some added support along the way.

The Nike Corporation is his major sponsor and Wheaties his biggest endorsement.

A sports writer told him he'd been stocking up on Wheaties ever since the Clay-adorned cereal boxes appeared in his local super market.

"Thanks for that," said Clay. "I'm grateful. Every little bit counts."