-- U.S. track and field star Maurice Greene, the world's dominant sprinter over the past decade, advocated on Monday a lifetime ban for athletes who test positive for performance-enhancing drugs and predicted that any athlete linked to the BALCO scandal would struggle under the specter of wrongdoing during the Olympics in Athens.

"I think there is no room in our sport for drug cheaters whatsoever," Greene said. "I don't think a year ban or two-year ban is enough for our sport. I think it should be a lifetime ban if you get caught even once on a serious drug. I stand behind our drug system in whatever they want to do."

Greene also acknowledged that he had broken a bone in his leg during a motorcycle accident two years ago, though he denied such rumors at the time. Brimming with confidence and conviction, he not only proclaimed himself 100 percent recovered but also guaranteed he would win the gold medal in his signature event, the 100 meters, in Athens this August.

Greene made the remarks during a news conference in New York, one day after sprinter Marion Jones vowed to file suit if she were barred from the Athens Olympics on the mere suspicion of drug use, as is possible under a new policy adopted by the U.S. Anti-Doping Agency.

Jones, who won five medals at the 2000 Olympics in Sydney, was drawn into the BALCO controversy after a check from her account surfaced in the federal government's investigation of the Bay Area Laboratory Co-Operative, which is suspected of manufacturing a steroid designed expressly to avoid detection in drug tests. Jones was both firm and poised Sunday in insisting that she has never used a banned substance.

Said Greene: "If your name came up in that situation over there, you're afraid right now. . . . You can act [poised] all you want, but in the back of your mind, you just have something else on your plate that you have to deal with, and that's going to take away from the mental aspect of what you have to get ready for."

The new policy of banning athletes for something less than a failed drug test (in USADA's parlance, a "non-analytical positive") has several athletes uneasy. Many say they are eager to see their sport's integrity restored but question whether punishing athletes based on circumstantial evidence, rather than a failed drug test, is fair.

"We're faced with a situation where you have people who were taking a synthetic steroid that was designed in a lab; it was designed so that the test could not detect it," said hurdler Allen Johnson. "Knowing that, what do you do? Is it fair to ban someone who has not tested positive? Of course not! At the same time, if you know someone has possessed something that is not detectable by a drug test, what do you do? That's the billion-dollar question in 2004."

Greene voiced unqualified support of the USADA's efforts to root out users of performance-enhancing drugs. Asked if he thought any well known track and field athletes could be barred from Athens because of the drug issue, Greene said: "Very well might be. My thing is this: If you don't deal with people or anything like that, you shouldn't have anything to worry about."

Winner of two gold medals at Sydney, Greene holds three of the four fastest times in history in the 100 meters. But the world's former fastest man heads to Athens with much to prove, having performed erratically over the past two years.

He revealed that the broken left leg, and the tendinitis and hamstring ailments that followed during his recovery, were partly to blame.

Greene said he was astride his Suzuki motorcycle idling in traffic on a congested Los Angles freeway when a car sideswiped him. The impact knocked him from the motorcycle, and X-rays later revealed a broken fibula. No police report was filed, and Greene said he didn't acknowledge it publicly because he was in contract talks at the time.

He was hardly circumspect Monday, declaring that he wanted to be known as the greatest sprinter of his time and modeling the new tattoo on his right biceps, which featured a lion's head with the letters "G-O-A-T" in its mane. "I'm a Leo, for one," Greene explained. "The track is my jungle, and the lion is the king of the jungle." The letters, he said, stood for "Greatest of All Time."

Such brashness proved unpopular at the 2000 Games in Sydney, where Greene and his teammates drew jeers after wrapping themselves in the American flag in a wild celebration after winning the gold medal in the 400-meter relay.

U.S. Olympic officials have asked American athletes to temper their displays of emotion in Athens, wary of inflaming anti-American sentiment.

Greene said he hadn't been spoken to directly but understood that footage of the relay team's celebration was included in a USOC video about how not to behave in Athens. "We didn't mean to offend anyone," Greene said. "We had accomplished something that was so hard to us. That thing just happened."

This year Greene plans to compete only in the 100 meters and relay. Asked to handicap the 100-meters field, Greene cited Shawn Crawford and Justin Gatlin among those running well, but added that everyone in the field would be competing for the silver medal.

"I say I win without a doubt. Very convincingly," Greene said.

His omission of sprinter Tim Montgomery was glaring, and Greene seemed to delight when asked why he hadn't mentioned his rival and the current world record holder among the contenders. Montgomery, the father of Jones's 11-month-old son, has also been called to testify before the grand jury that is examining BALCO.

"Tim has got to get consistent for anybody to pay attention to him because he doesn't win when he's supposed to win," Greene said. "He doesn't do the things he says he's going to do."

Noting that Montgomery ran his two fastest times when the wind was blowing in his favor, Greene seemed to brush the achievement aside. "He's the luckiest man in track and field history," he said.

Maurice Greene guarantees he will win 100 meters in Summer Games. Maurice Greene, left, with J.J. Johnson: "I say I win [the 100 meters in Athens] without a doubt. Very convincingly."