Animal Kingdom suffers leg problem

Kentucky Derby winner Animal Kingdom has developed lameness in his left hind leg and won't run in the $10 million Dubai World Cup on March 31.

Trainer Graham Motion wrote on his Twitter feed that Animal Kingdom was sore after a weekend workout at Palm Meadows Training Center in Boynton Beach, Fla. Tests were being done Monday to determine the severity of the injury.

It's the same leg Animal Kingdom injured after finishing sixth in the Belmont Stakes last year. He missed the rest of the year and returned to racing last month with a win at Gulfstream Park.

Team Valor International CEO Barry Irwin says the injury is a ''crushing blow for our company and our partners as well as our trainer.'' If Animal Kingdom recovers, Irwin says the 2013 World Cup is a possibility.