Halfbridled, the 2-year-old filly champion of 2003, was scratched from the April 30 Kentucky Oaks (gr. 1) the morning of the race after having tied up (tying up is basically form of cramping). She was scratched from the April 3 Ashland Stakes (gr. I) at Keeneland for the same reason.Trainer Richard Mandella said the Unbridled filly was in discomfort after a one-mile Friday morning jog, in which she appeared fine. "But when she came back on the shedrow and started to walk, you could see she was cramping, her stomach was tight," Mandella said. "She didn't tie up much, but it was enough. I just can's run her -- in this race or any other race -- if she isn't right."Halfbridled, trained by Richard Mandella, was among the top choices in the Oaks, which would have been her third start of the year. Halfbridled, by Unbridled, finished second in the Santa Anita Oaks (gr. I) and Stonerside Beaumont Stakes (gr. II) in her first two starts of the season.Last year, Halfbridled won all four of her starts, including the Breeders' Cup Juvenile Fillies (gr. I). She has earned $959,400.Madcap Escapade is the 3-1 morning-line favorite for the Oaks. Ashado is listed as the second choice at 4-1, while Halfbridled was third at 9-2.Halfbridled, owned by Wertheimer Farm, was favored in each of the Oaks Future Wager pools offered by Churchill Downs.Louisiana Derby winner (gr. II) Wimbledon was scratched from Saturday's Kentucky Derby (gr. ) after swelling on the outside of the left front tendon was detected when stable personnel removed bandages from the colt Friday morning.