Kentucky Derby entrant King Guillermo did not train Thursday morning at Churchill Downs and, in a developing story, trainer Juan Carlos Avila said the colt has "a little problem." Avila declined to elaborate on the nature of the issue, but indicated that the colt would be thoroughly examined by a veterinarian that day, and that more information on his status would be forthcoming later Thursday. :: Become a DRF Bets member and get DRF's Kentucky Derby VIP Package for free “It’s a big race, and a little problem is a big problem for me,” Avila said. King Guillermo won the Grade 2 Tampa Bay Derby in March and finished second in a division of the Grade 1 Arkansas Derby on May 2 in his final prep. He had been galloping regularly at Churchill Downs, and did so Wednesday morning. This story will be updated as it develops.