LOUISVILLE, Ky. — Suddenly, the Kentucky Derby is wide open.
Favorite Omaha Beach was scratched because of a breathing problem Wednesday night, leaving a pair of Hall of Famers on the sideline — trainer Richard Mandella and jockey Mike Smith.
Churchill Downs oddsmaker Mike Battaglia revised the morning line to make Game Winner the 9-2 favorite for the 1¼-mile race Saturday.
Improbable and Roadster were installed as the co-second choices at 5-1, giving five-time Derby-winning trainer Bob Baffert the top three choices in the 20-horse field.
Mandella said Omaha Beach developed a cough and a subsequent veterinary exam showed the colt has an entrapped epiglottis. It’s generally not life- or career-threatening and is typically corrected with minor surgery.
‘‘It’s been a devastating thing, but we have to do what’s right for the horse,’’ said Mandella, who has never won the Derby with six previous starters.
The trainer said Omaha Beach will have surgery in Kentucky in the next few days and will be sidelined for two to three weeks. The ordeal will knock him off the Triple Crown trail.