By BOB "RAILBIRD" ROBERTS CLEVELAND, Ohio -- More often than not, the Kentucky Derby proves to be a grueling test. The mile and a quarter distance often exposes pedigree shortcomings as it drains participants of their energy. They end up needing a vacation from the starting gate. It's been seven weeks since the 143rd Kentucky Derby went to the post. Five of the 20 thoroughbreds have yet to run back, while the 15 that have raced combine for just two victories in 17 subsequent starts. After taking a deep breath, four of the Run for the Roses runners will be at Thistledown for Saturday's $500,000 Ohio Derby (Grade III), hopeful of putting their careers back on track by collecting the $300,000 first prize. Heading the pack of nine is Brad Grady's Girvin, a dark brown colt that never got to run his race at Churchill Downs after being jostled shortly after the start and then nearly sent to his knees when caught in traffic turning for home. He ended up 13th, beaten nearly 20 lengths. Thistledown oddsmaker Nick Mascio has installed Girvin the Ohio Derby's 2-1 morning line favorite based on his sparkling record prior to the Louisville debacle. The son of Tale of Ekati was on his game when he won back-to-back Grade II stakes at the Fair Grounds, the Risen Star and the Louisiana Derby. "He had a terrible trip in the Kentucky Derby," said trainer Joe Sharp. "The sloppy track didn't help and then he was nearly dropped at the 3/8th pole when in heavy traffic." Sharp says that Girvin, a winner of three of five starts and $874,000, has regained his energy after a three-week break. He signaled his readiness for the Ohio Derby by working five furlongs in a minute last Saturday. "It was his best work in quite awhile," said Sharp. Hall of Fame jockey Mike Smith, who rode Girvin in the Kentucky Derby, will ride him at Thistledown. "Mike is high on him," said Sharp. "He said I should have run him back in the Preakness or Belmont." The other Run for the Roses also-rans ready to run in the Ohio Derby are Irap, winner of Blue Grass, but 18th in the Derby, Untrapped, 12th in the Derby, and Spiral Stakes winner Fast and Accurate, 17th in the Derby. Stow's Ron Paolucci will run a