Maurice Greene, the 2000 Olympic 100-meter champion, sees Usain Bolt as \"dangerous\" but not as fit as in 2008 and said Tuesday he expects a dramatic 100-meter final at the London Olympics. Two days after 2004 Olympic champion Justin Gatlin and 2007 world champion Tyson Gay booked 100m berths at London for an expected showdown with reigning Olympic champion Bolt, Greene sized up the men who followed in his footsteps. \"The race in London is going to be a lot closer than a lot of people think,\" Greene said. \"It\'s going to be a really exciting race.\" Speaking on a rest day at the site of the US Olympic Track and Field Trials, Greene, who turns 38 next month, said he does not see Bolt lowering his world record of 9.58 seconds from Berlin in 2009. \"I\'m going to tell you right now, he can\'t do that,\" Greene said. Greene, a US sprint legend whose nickname was the \"Kansas Comet\", is proof that an Olympic can match his time from four years earlier, however. Greene won gold at Sydney in 9.87 and took bronze in 2004 at Athens in the same time. \"He has done it before so you have to prepare accordingly,\" Greene warned Olympic sprinters. \"If you want the gold, you have to be prepared to go to that area.\" Bolt will not lack for motivation at London simply because he already won Olympic gold, and in overwhelming fashion, at Beijing, according to Greene. Greene cited Bolt\'s false start disqualification in last year\'s 100m world final as enough inspiration to make him a foe to fear in the London final. \"Usain is talking about his legacy,\" Greene said. \"He wants to prove he should have won when he was knocked out. I don\'t think he would have won. I know when someone has something to prove, he is dangerous.\" Bolt, 25, faces the Jamaican Olympic trials next weekend at Kingston but the 2008 Olympic 100 and 200 champion and reigning world 200 champion lacks the sizzle that saw him win 100 gold at Beijing in 9.69. \"I look at people. I analyze their races. He hasn\'t shown to me to be in that type of shape that he was in 2008,\" Greene said. \"If he is in that kind of shape he\'s going to win. I don\'t think he\'s in that kind of shape. He\'s having problems from zero to 65 (meters). From there to the finish, that\'s just him. You have to be with him at 70.\" Bolt owns the fastest times in the world this year, 9.76 to win in Rome last month and 9.79 to win at Oslo earlier this month. Gatlin, 30, is next at a career-best 9.80 from his victory Sunday at the US trials. Then come Jamaicans Yohan Blake at 9.84 and Asafa Powell at 9.85 with Gay\'s runner-up trials time of 9.86 next, level with Trinidad and Tobago\'s Keston Bledman. Greene, who held the world record at 9.79, does not favor the chances of either US runner against Bolt, but he notes Gay is coming off right hip surgery last year that allowed him to return only this month after nearly a year off. \"I think it\'s equal,\" Greene said. \"Tyson has run faster than Justin but he\'s still coming off that surgery. His biggest thing is to get healthier. I don\'t think he\'s 100 percent. \"I don\'t think if you are going into a gunfight that you go in there with four bullets when everybody else has got nine. You\'re going to need those extra bullets.\" Gay, whose personal best was 9.69 in 2009 at Shanghai, has had fewer races to tax his body, which could help in London. \"He stopped some of that wear and tear on his body. It\'s probably a good thing,\" Greene said. \"It\'s a difficult task for him. It remains to be seen if he can do it.\"