The number of horses expected for the April 13 Arkansas Derby (gr. II) expanded to 12 Wednesday with the addition of Dial A Hero, It'sallinthechase, Like A Hero, and Guppie's Secret. But Oaklawn Park officials are beginning to fear the connections of expected starter Ocean Sound may opt for the Blue Grass Stakes (gr. I) instead. Guppie's Secret earned a bullet for his 1:13 3/5 six furlongs Wednesday at Oaklawn, convincing trainer Lynn Whiting to try the Derby. Whiting also said Calvin Borel will be in the irons."Everything I've seen about Guppie's Secret has been positive, and his work this morning was excellent," Whiting said. "If he gets excluded from the Derby, or if he draws poorly, we can use the Northern Spur as a backup."The Arkansas Derby is limited to 14 starters.James Lopez will guide Dial A Hero and Gerald Melancon has the call on It'sallinthechase.Ocean Sound finished second in the Rebel Stakes (gr. III), the last local prep for the local Derby, following which the Irish-bred colt was reported to be pointed toward the Arkansas Derby. Oaklawn Park officials now report that trainer James Cassidy may be considering Keeneland's Blue Grass Stakes as well.The others expected for the 1 1/8-mile race are Dusty Spike, Bay Monster, Rebel winner Windward Passage, Wild Horses, Private Emblem, Holdthehelm, and Mr. Mellon.