KENTUCKY DERBY DOINGS

Trainer Shug McGaughey fields questions from the media after the morning excercise session in preparation for the 139th Kentucky Derby at Churchill Downs on April 29, 2013 in Louisville, Kentucky. (Photo by Matthew Stockman/Getty Images)

Marvin Abrego rides Frac Daddy during the morning exercise session in preparation for the 139th Kentucky Derby at Churchill Downs on April 29, 2013 in Louisville, Kentucky. (Photo by Matthew Stockman/Getty Images)

Gary Stevens rides Oxbow during the morning exercise session in preparation for the 139th Kentucky Derby at Churchill Downs on April 29, 2013 in Louisville, Kentucky. (Photo by Matthew Stockman/Getty Images)

Jennifer Patterson rides Orb (L) during the morning exercise session in preparation for the 139th Kentucky Derby at Churchill Downs on April 29, 2013 in Louisville, Kentucky. (Photo by Matthew Stockman/Getty Images)

Trainer D. Wayne Lukas fields questions from the media after the morning excercise session in preparation for the 139th Kentucky Derby at Churchill Downs on April 29, 2013 in Louisville, Kentucky. (Photo by Matthew Stockman/Getty Images)

Trainer Todd Pletcher looks at Kentucky Derby entrant Revolutionary at Churchill Downs Monday, April 29, 2013, in Louisville, Ky. (AP Photo/Charlie Riedel)

Nick Bush rides Kentucky Derby entrant Charming Kitten for a workout at Churchill Downs Monday, April 29, 2013, in Louisville, Ky. (AP Photo/Charlie Riedel)

Exercise rider Peter Shelton rides Kentucky Derby entrant Itsmyluckyday for a workout at Churchill Downs Monday, April 29, 2013, in Louisville, Ky. (AP Photo/Morry Gash)

Steam rises as horses are washed after their morning workouts at Churchill Downs Tuesday, April 30, 2013, in Louisville, Ky. (AP Photo/Charlie Riedel)