"The shin is sore and it shows the beginning of a little stress fracture, so we had to stop on him," Mandella said. "This is extremely disappointing because he was the perfect Derby horse."
Mandella said the injury would sideline Crown of Thorns for several months, eliminating him from all three Triple Crown races. The Kentucky Derby Presented by Yum! Brands (gr. I) is May 3; the Preakness (gr. I) is May 17 at Pimilco; and the Belmont (gr. I) is June 7.
Crown of Thorns is a bay colt from the first crop of Repent, out of the Thunder Gulch mare Crowning Touch. He was purchased by owner B. Wayne Hughes at the Ocala Bredders Sales Co.'s 2-year-olds in training sale for $300,000 last March.
Crown of Thorns was bred in Florida by Cloverleaf Farms II. Unraced Crowning Touch is a half-sister to champion sprinter Smoke Glacken and multiple graded winner Smoky Glacken.
After finishing fifth in his debut in December, Crown of Thorns broke his maiden by seven lengths before winning the Lewis by 2 1/2 lengths, establishing himself as one of the leading Derby contenders. He has earned $149,640.