Fusao Sekiguchi's Fusaichi Samurai, co-future book favorite for the Kentucky Derby (gr. I) despite only a maiden victory to his credit, has sustained a pulled muscle in his left hind leg, suffered in a workout, and has been taken off the Derby trail, trainer Neil Drysdale said Friday."After his last work, he was stiff in his left hind," Drysdale said. "I talked to Mr. Sekiguchi a couple of days ago and we decided to take him off the Triple Crown trail and give him some time off."Fusaichi Samurai was the 7-1 co-favorite for the Derby at Bally's after his smashing maiden victory at Hollywood Park on Dec. 11, in which he won as he pleased by two lengths in a swift 1:15.54 for the 6 1/2 furlongs.Sekiguchi purchased the son of Fusaichi Pegasus for a world record $4.5 million at the Fasig-Tipton Calder 2-year-old sale from Kirkwood Stables, agent. He originally had been bought as a yearling for $270,000 by Nick Zito for Robert LaPenta, who pinhooked the colt the following year.Sekiguchi owned Fusaichi Pegasus, who captured the 2000 Kentucky Derby, Wood Memorial (gr. II), and Jerome Handicap (gr. II).Fusaichi Samurai is out of the Storm Cat mare Hidden Storm.