AUBURN, Wash. - An ankle injury will prevent Longacres Mile champion Assessment from running in the 2009 Breeders' Cup and keep him sidelined until next spring, trainer Howard Belvoir said Friday.\nAssessment chipped a bone in an ankle during a six-furlong workout on Sept. 4 and underwent surgery six days later. The procedure was performed at Emerald Downs' veterinary clinic by Dr. Robert Schneider, a specialist in equine orthopedic surgery at Washington State University.\n"He was in surgery for a couple of hours and came out good," Belvoir said. "Everything's fine - he just needs some R and R. We'll start back jogging in about 60 days and go back into training in February."\nAssessment's victory Aug. 16 in the Grade 3, $300,000 Longacres Mile, part of the Breeders' Cup's Win and You're In program, launched him on a path toward the $2 million Breeders' Cup Dirt Mile on Nov. 7 at Santa Anita. He worked four furlongs Aug. 27, and went six furlongs in 1:11.20 the day he was injured.\nHis next start was expected to come in the Grade 1, $350,000 Goodwood Stakes at Santa Anita on Oct. 10, and regular rider Gallyn Mitchell was scheduled to accompany him to Southern California.\n"He was dead sound," Belvoir said. "He probably did it in the workout, because [the chip] wasn't there before. But that's what happens in this world. All it takes is one step, one bad step."\nLikely to be named horse of the meeting when Emerald's season wraps next Sunday, Assessment won the one-mile Budweiser Emerald Handicap on June 21 and the nine-furlong Mount Rainier Handicap on July 26, the two key steppingstones to the Longacres Mile. A Kentucky-bred 5-year-old gelding by Jump Start, he has won 7 of 25 career starts and earned $355,980 for owners Lou and Diane Tice of Seattle. Belvoir said the owners took the news in stride.\n"Lou's a champ, he's a good owner," Belvoir said. "He knows athletics, and he knows what can happen. Fortunately, it didn't happen before the Mile."\nAssessment won a 5 1/2-furlong allowance race on opening night and then was first or second in six consecutive stakes races ranging in distance from six furlongs to 1 1/8 miles.\n"I don't think a horse could have a better year," Belvoir said. "He got into trouble a couple of times and that cost him a race or two, I think, but it was a great year for him. When the gate opened, he showed up."